PROSPECTUS                                Filed Pursuant to Rule 424(b)(3)
                                               Registration No. 333-114062



                          ALLIANT ENERGY CORPORATION
                            SHAREOWNER DIRECT PLAN

                       4,593,774 Shares of Common Stock

      We are offering participation in our Shareowner Direct Plan.  The plan
provides you with a variety of options, including:

0     automatic reinvestment of all or a portion of your cash dividends paid
      on shares of our common stock in additional shares of our common stock;

0     the ability for persons who are not shareowners to purchase their
      initial shares of our common stock;

0     a means of purchasing additional shares of our common stock by making
      optional cash investments of up to $360,000 per calendar year, including
      any initial investment;

0     a free custodial service for depositing your common stock certificates
      with the administrator of the plan for safekeeping;

0     the ability to transfer or make gifts of your shares of our common stock
      at no charge; and

0     the ability to sell your shares of our common stock through the plan.

      The plan provides that shares of our common stock may be purchased for
participants from us or in the open market or in privately negotiated
transactions.  The price of shares of common stock purchased under the plan
will be either:

0     the average of the high and low sale price of shares of our common stock
      as reported on the New York Stock Exchange on the date of purchase if
      newly issued shares are purchased from us; or

0     the weighted average of the price paid for shares of our common stock if
      purchased on the open market or in privately negotiated transactions.

No brokerage commissions, fees or service charges are charged to you in
connection with purchases of shares under the plan.  You will bear the cost
of brokerage fees and related service charges relating to sales of shares
under the plan, and participants who reinvest dividends paid on our common
stock are currently charged a fee of $0.50 per quarter to defray in part the
administrative costs of the plan.

      Our common stock is listed on the New York Stock Exchange under the
symbol LNT.  The closing price of our common stock on February 1, 2005 on
the New York Stock Exchange was $27.65 per share.

      Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved of these securities or determined if
this prospectus is truthful or complete. Any representation to the contrary
is a criminal offense.




                             ____________________

               The date of this prospectus is February 14, 2005.



                                       



                               TABLE OF CONTENTS

                                                                Page

The Company.......................................................3
Use of Proceeds...................................................3
Summary of Plan Features..........................................3
The Plan..........................................................4
      Purpose.....................................................4
      Plan Administration.........................................4
      Enrollment Procedures.......................................5
      Transfer of Shares From Street Name.........................5
      Initial Investments and Optional Cash Investments...........5
      Methods of Investment.......................................6
      Dividend Reinvestment Options...............................7
      Purchase of Common Stock....................................8
      Price to Participants.......................................9
      Sale of Common Stock........................................9
      Custody of Stock and Issuance of Stock Certificates.........9
      Share Safekeeping...........................................9
      Gift/Transfer of Shares Held in the Plan...................10
      Withdrawal and Termination.................................10
      Stock Splits, Stock Dividends and Rights Offerings.........11
      Voting Rights..............................................11
      Fees and Charges...........................................11
      Statements and Reports.....................................11
      No Right to Draw Against Account...........................12
      Duties and Responsibilities................................12
      Change or Termination of the Plan..........................12
      Our Termination of an Account..............................12
      Interpretation of the Plan.................................12
      Governing Law..............................................12
Federal Income Tax Consequences..................................12
      General Considerations.....................................13
      Tax Withholding............................................13
Rights to Purchase Common Stock..................................14
Legal Matters....................................................14
Experts..........................................................14
Where You Can Find More Information..............................15
                           ______________________________

     You  should  rely only on the  information  contained  or  incorporated  by
reference in this prospectus. We have not authorized any other person to provide
you with  different  information.  If  anyone  provides  you with  different  or
inconsistent information,  you should not rely on it. We are not making an offer
to sell  these  securities  in any  jurisdiction  where the offer or sale is not
permitted.  You should assume that the information  appearing in this prospectus
and  the  documents  incorporated  by  reference  is  accurate  only  as of  the
respective  dates of those documents in which the information is contained.  Our
business,  financial  condition,  results or  operations  and prospects may have
changed since those dates.

                          _______________________________

      Unless we otherwise indicate or unless the context requires otherwise, all
references in this prospectus to we, our, us or similar references mean
Alliant Energy Corporation.



                                       2

    

                                  
                                The Company

      We are an energy-services provider engaged primarily in public utility
operations in both the Midwest and internationally.  We also have significant
non-regulated domestic and international operations.  Through our 
subsidiaries and partners, we provide electric, natural gas, steam and water
services, and various other energy-related products and services to more than
three million customers worldwide.  Our domestic utility business includes
Interstate Power and Light Company and Wisconsin Power and Light Company and
is engaged principally in:

0     the generation, transmission (Interstate Power and Light Company only),
      distribution and sale of electric energy;

0     the purchase, distribution, transportation and sale of natural gas; and

0     the provision of water services, steam services to certain customers in
      one community in Iowa, and various other energy-related products and
      services including construction management services for wind farms.

      The principal markets for our domestic utility business are located in
Iowa, Wisconsin, Minnesota and Illinois.

      We are a registered public utility holding company subject to regulation
by the Securities and Exchange Commission under the Public Utility Holding
Company Act of 1935 and are subject to the regulatory provisions of that Act.

      Our principal executive offices are located at 4902 North Biltmore Lane,
Madison, Wisconsin 53718, and our telephone number is (608)458-3311.

                               Use of Proceeds

      We have no basis for estimating either the number of authorized but
unissued shares of common stock that we will ultimately sell pursuant to the
plan or the prices at which we will sell the shares.  Any net proceeds we
receive from the sale of shares under the plan will be added to our general
funds and used for general corporate purposes.  We will not receive any
proceeds from the sale of shares under the plan that are acquired on the open
market or in privately negotiated transactions.

                            Summary of Plan Features

      Some of the features of the plan, which are described in greater detail
under The Plan below, are:

0     If you do not presently own shares of common stock, then you may become
      a plan participant, assuming some qualifications are met, by completing
      an authorization form and making an initial cash investment of not less
      than the amount specified on the authorization form nor more than
      $360,000.

0     If you participate in the plan, then you may acquire additional shares
      of common stock by making optional cash investments in amounts not less
      than $25 per investment nor more than $360,000 per calendar year,
      including any initial investment.  The investment amount can be
      automatically deducted from your bank account or it can be submitted by
      mail.

0     If you participate in the plan and are our employee or an employee of
      one of our subsidiaries, then you may also acquire additional shares of
      common stock by making optional cash investments through payroll
      deductions.  The minimum deduction per pay period is the amount
      specified on the payroll withholding form. You may not make optional
      cash investments through payroll deductions of more than $360,000 per
      calendar year, including any initial investment and any optional cash
      investments made by means other than payroll deduction.



                                       3



0     If you participate in the plan, then you may acquire additional shares
      of common stock automatically by reinvesting all or a portion of your
      cash dividends paid on shares of common stock you then own.

0     If you participate in the plan, then you may deposit your common stock
      certificates, at no cost, with the plan administrator for safekeeping.

0     If you participate in the plan, then you may have your cash dividends
      electronically deposited into your checking or savings account.

0     If you participate in the plan, then you may sell your shares of common
      stock held by the plan through the plan administrator.

0     Dividends are calculated on all full and fractional shares of common
      stock in the plan.

0     Personal record keeping is simplified by our issuance of quarterly
      statements indicating account activity.  You should retain these
      statements for tax purposes.

0     If you participate in the plan, then you may transfer or make gifts of
      shares of common stock at no charge.

                               The Plan

      The following are the terms and conditions of the plan.

Purpose

      The purpose of the plan is twofold.  First, the plan provides our
shareowners of record, other investors who choose to become shareowners of
record and our employees and the employees of our subsidiaries with a simple,
convenient and economical method to purchase shares of common stock and to
reinvest all or a portion of their cash dividends in additional shares of
common stock. Second, the plan provides us with the ability to sell our
authorized but unissued shares of common stock to participants in the plan,
which will raise funds to increase our equity base for general corporate
purposes.

Plan Administration

      Through our Shareowner Services Department, the administrator of the
plan, we administer the plan, keep records, send statements of account
activity to participants and perform clerical and ministerial duties related
to the plan. An independent agent, which is not an affiliate of ours,
designated by the administrator will make purchases and sales of shares of
common stock for the plan in the open market or in privately negotiated
transactions.  Subject to applicable securities laws and some limitations,
the independent agent will have full discretion as to the timing of, and all
matters relating to, purchases and sales of shares of common stock for the
plan other than for the purchase from us of authorized but unissued shares.

      The administrator will establish and maintain a separate account under
the plan for each participant.  We will credit to your account all shares of
common stock, including any fractional shares, computed to four decimal
places, purchased for a participant under the plan, and any shares a
participant deposits through the plan's share safekeeping service.

      You should direct all inquiries and instructions concerning the plan to:

      Alliant Energy Shareowner Services
      P.O. Box 2568
      Madison, WI 53701-2568
      Telephone:(608)458-3110
                (800)356-5343
      Fax:      (608)458-3321
      Internet:  www.alliantenergy.com

      All correspondence should include your shareowner account number,
taxpayer identification or social security number and daytime telephone
number where you may be contacted during normal working hours to facilitate a
prompt response.



                                       4




Enrollment Procedures

      Shareowners

      If you are currently a shareowner of record, then you may enroll in the
plan at any time by completing and returning an authorization form to the
administrator.  You should direct requests for authorization forms to the
administrator, either by telephone, in writing or through the internet.

      "Street Name" Holders

      If you own shares of common stock that are held on your behalf by a
bank, broker, trustee or other agent, then you may enroll in the plan by
registering one or more shares of common stock directly in your name and by
returning a completed authorization form to the administrator. See "Transfer
of Shares from Street Name."

      Non-Shareowners

      With limited exceptions described below, if you are not currently a
shareowner of record, then you may enroll in the plan by completing and
returning an authorization form to the administrator together with an initial
investment of at least $250, but not more than $360,000, or by authorizing
automatic withdrawals that will occur twice a month ("automatic investments")
of at least $25, in either case which will be used to purchase shares of
common stock for your plan account.  See "Initial Investments and Optional
Cash Investments" and "Methods of Investment."

      Employees

      With limited exceptions described below, any of our employees or
employees of our subsidiaries may enroll in the plan at any time by
completing and returning an authorization form to the administrator or by
enrolling in the same manner as any other eligible investor described above.

      Exceptions

      We reserve the right to prohibit participation in the plan by
non-shareowners who reside in a state where participation in the plan by
non-shareowners who reside in the state would require us to take special
action under the securities or "blue sky" laws of the state and we have not
yet taken the required action.  We also reserve the right to prohibit
participation in the plan by any investor, whether or not a holder of record
of shares of common stock, who is a citizen or resident of a country other
than the United States, if his or her participation would violate local laws
and regulations applicable to us or the prospective participant.  In any such
case, the administrator will return any authorization form and initial
investment tendered by any non-shareowner who resides in such state or
country.

      General

      We will process authorization forms as promptly as practicable.
Participation in the plan will begin after the administrator has reviewed and
accepted a properly completed form.

Transfer of Shares From Street Name

      If you are a beneficial owner of common stock whose shares are
registered in the name of a bank, broker, trustee or other agent, then you
may participate in the plan with respect to these shares by either:

0     transferring the shares to a plan account by directing your agent (for
      example, your bank, broker or trustee) to register the shares directly
      in your name and having the agent deliver a certificate to you, or

0     instructing your agent to transfer the shares to the administrator to be
      deposited into the plan for "share safekeeping" for credit to your plan
      account.  See "Share Safekeeping."

Initial Investments and Optional Cash Investments

      If you are not currently a shareowner of record, then you must make an
initial investment of at least $250, but not more than $360,000, in the form
of a personal check or money order, automatic investment of at least $25 or,
for employees, payroll deduction of at least the amount specified on the
payroll withholding form, and you must include your initial investment with
the completed authorization form you return to the administrator.  See
"Methods of Investment."


                                       5




      Once you are enrolled in the plan, you may purchase additional shares of
common stock using the plan's optional cash investment feature.  You must
make optional cash investments in amounts of not less than $25 per investment
and may not aggregate more than $360,000 per calendar year, including any
initial investment, whether by check or automatic investment.  We will not
waive these restrictions; however, the $25 minimum is not applicable to
employee participants who make investments through payroll deductions.  You
have no obligation to make an optional cash investment at any time, and the
amount of your investments may vary from time to time.

      The administrator must receive authorization forms, which are subject to
our review, with initial investments at least five business days prior to the
next investment date (as defined under "Purchase of Common Stock").  The
administrator will invest initial investments and optional cash investments
on the next investment date, provided the administrator receives such
investments at least five business days prior to that investment date.

      We will not pay interest on any initial investments or optional cash
investments received and held for investment under the plan.  Therefore, it
is to your benefit to mail an initial investment or an optional cash
investment so that the administrator receives it shortly, but not less than
five business days, before an investment date.  To receive dividends, the
administrator must have received and invested an initial investment or an
optional cash investment on the investment date prior to the dividend record
date.

      Upon written request, we will refund your initial investment or any
optional cash investment, provided we receive your request at least two
business days prior to the investment date following receipt of your
investment.  However, we will not make a refund until we actually receive the
funds.

Methods of Investment

      Your total annual investment cannot exceed $360,000 per calendar year
and must be made in U.S. dollars.  For the purpose of applying this limit,
all investments during any calendar year, including initial and optional cash
investments, but excluding dividend reinvestments and deposits of shares in
the plan's share safekeeping service, are aggregated.  We will not pay any
interest on amounts we hold pending investment.

      Check Investment

      You may make initial investments and optional cash investments by
personal check or money order payable to "Alliant Energy."  Initial
investments are subject to our collection for the full face value in U.S.
funds.

      If a check is returned unpaid for any reason, then we will consider the
request for investment of these funds null and void.  If any shares have been
purchased with these funds, then the administrator will be entitled to remove
those shares from the participant's account and sell those shares to satisfy
the balance of the uncollected funds.  If the net proceeds from the sale are
insufficient to cover this balance, then we will, in addition to any other
rights we may have, be entitled to sell any additional shares from your
account that may be necessary to satisfy the uncollected balance.

      Automatic Investment

      You may make automatic investments twice a month, whether initial or
optional cash investments, of at least $25 by electronic funds transfer from
a predesignated account with a U.S. financial institution.  To initiate
automatic investments, you must complete and return to the administrator an
automatic investment form and an authorization form, as well as deliver to
the administrator a voided blank check or a savings deposit slip for the
account from which funds are to be drawn.  You may obtain automatic
investment forms from the administrator.  Automatic investments will be
initiated as promptly as practicable.  Funds then will be drawn from your
designated account on the tenth and twenty-fifth days of each month, or, if
the tenth or twenty-fifth day falls on a weekend or bank holiday, the first
business day thereafter, and will be invested in common stock on the next
investment date.


                                       6



      You may change the amount of your future automatic investments by
completing and submitting to the administrator a new automatic investment
form.  You may terminate your automatic investments by notifying the
administrator by phone, in writing or through the internet.  To be effective
with respect to the next automatic investment date, the administrator must
receive the new form or notice at least six business days preceding that date.

      Electronic direct deposit of cash dividends that you elect to receive
also is available through the plan.

      Payroll Deductions

      Our employees or employees of our subsidiaries may also make
investments, whether initial or optional cash investments, by means of
payroll deduction, and the $250 and $25 minimums for initial investment and
optional cash investments, respectively, will not apply to investments made
through payroll deductions.  To initiate payroll deductions, the employee
must complete and return to the administrator a payroll withholding form and
an authorization form.

      The payroll withholding form, which allows participating employees to
decide the dollar amount to be deducted from their paychecks for each pay
period, will become effective as promptly as practicable.  Deductions will be
used to purchase full and fractional, computed to four decimal places, shares
of common stock on the next investment date.  The minimum deduction per pay
period is the amount specified on the payroll withholding form.

      Payroll deduction authorizations will remain in effect until cancelled
or modified by the employee, which a participating employee may accomplish by
completing and returning a new payroll withholding form indicating the change
desired.  To be effective with respect to the next payroll deduction, the
administrator must receive the new payroll withholding form at least six
business days preceding that date.

Dividend Reinvestment Options

      The authorization form allows you to choose a reinvestment option for
participation in the plan.  If you do not specify otherwise, then your
account will be enrolled for full dividend reinvestment.  By choosing the
appropriate box, you may select:

Full Dividend        Reinvest all cash dividends on all certificated shares
Reinvestment->       held by you and on all shares credited to your plan
                     account.  You may make optional cash investments at any
                     time as described in this prospectus.


Partial Dividend     Receive cash dividends on a specified number of
Reinvestment->       your shares of common stock and reinvest the cash
                     dividends on the remainder of your shares. The shares
                     you specify to receive cash dividends may consist of a
                     combination of certificated shares and shares credited
                     to your plan account.  You may elect to have cash
                     dividend payments not reinvested paid by check or through
                     electronic direct deposit. You may make optional cash
                     investments at any time as described in this prospectus.


Optional Cash        Receive cash dividends on all of your shares of 
Purchases Only->     common stock, including both certificated shares
                     held by you and shares held by the plan and credited to
                     your plan account. You may make optional cash investments 
                     at any time.



                                       7




      If you participate in the plan's full or partial dividend reinvestment
option, then reinvestment will commence with the first dividend payable after
the dividend record date following your enrollment.  We will publicly
announce dividend record dates.

      If you wish to change your method of participation, then you must obtain
and complete a new authorization form and send it to the administrator.  To
be effective with respect to a particular common stock dividend, the
administrator must receive the new authorization form at least two business
days before the record date for the dividend.  If you elect to cease the
reinvestment of your dividends, then you may receive them by check or
electronic direct deposit.  You may also continue to have the administrator
hold your shares through the share safekeeping service, buy shares with
optional cash investments, and sell or transfer the shares as you desire.
See "Share Safekeeping," "Initial Investments and Optional Cash Investments,"
"Sale of Common Stock" and "Gift/Transfer of Shares Held in the Plan."

      On each applicable investment date, we will promptly, after deducting
withholding taxes, if any, and any administrative fees, combine and pay over
to the administrator all cash dividends payable on shares held by the
administrator for all participants who are reinvesting their dividends in the
plan.  The administrator will apply the dividends to the purchase of shares
of common stock.  The administrator will credit the proportionate number of
shares, computed to four decimal places, purchased by the administrator to
your account.

Purchase of Common Stock

      Reinvested common stock dividends, initial investments, optional cash
investments and proceeds, which will be treated regardless of the amount as
optional cash purchases, from the sale or redemption of common stock
subscription or other rights, if any, received by the administrator on behalf
of participants will be used to acquire either outstanding shares of common
stock or authorized but unissued shares of common stock from us, provided
that we are willing to sell the common stock.  Purchases of outstanding
shares of common stock on behalf of plan participants may be made on any
stock exchange in the U.S. where our common stock is traded, in the
over-the-counter market or by privately negotiated transactions on terms that
the independent agent for the administrator may reasonably determine at the
time of purchase.  Any shares purchased from us will be made in accordance
with applicable requirements.

      The administrator and its designated independent agent may combine your
funds with those of other participants for the purpose of purchasing shares.
Neither we nor any affiliated purchasers will exercise any direct or indirect
control or influence over the times when, or prices at which, the designated
independent agent may purchase common stock for the plan or the amount of
shares the designated independent agent may purchase.

      Purchases of shares of common stock under the plan will be made on or
about the following applicable "investment dates":

0     Each dividend payment date is an investment date for the reinvestment of
      cash dividends.

0     The first and fifteenth days of each month, or the first business day
      thereafter if the first or fifteenth day of the month falls on a weekend
      or holiday, are investment dates for initial investments and optional
      cash investments.

      Purchases may be made over a period of several days in the case of open
market purchases. All open market purchases will be aggregated for the
investment date.

      For a number of reasons, including observance of the rules and
regulations of the Securities and Exchange Commission or other regulatory
agencies requiring temporary curtailment or suspension of purchases, the
investment of all or part of the funds available in your account may be
delayed from time to time.  We will not pay any interest on funds we hold
pending investment.  However, shares of common stock will either be purchased
within 35 days of receipt of initial investments or optional cash investments
or funds will be returned to you.


                                       8



      We will credit your account with that number of shares of common stock,
including any fractional shares, computed to four decimal places, equal to
the total amount to be invested divided by the applicable purchase price per
share.

Price to Participants

      The price of newly-issued shares of common stock purchased from us for
participants will be the average, computed to four decimal places, of the
high and low sale prices of shares of common stock as reported on the New
York Stock Exchange on the applicable investment date.  If no trading occurs
on the New York Stock Exchange in the common stock on the applicable
investment date, then the price will be determined with reference to the next
preceding date on which the common stock is traded on the New York Stock
Exchange.  The price of shares of common stock purchased for participants on
the open market or in privately negotiated transactions will be the weighted
average price of all the shares purchased for the applicable investment
date.  If an investment under the plan is at any time made in both
newly-issued and already outstanding shares, then the shares purchased will be
allocated as proportionately as is practicable among the accounts of all
participants for whom funds are being invested at that time.

      Under the plan, you do not have the ability to order the purchase of a
specific number of shares, purchase of shares at a specified price or a
particular date of purchase, as could be done with respect to purchases
through a broker.

Sale of Common Stock

      You can sell all or part of your shares held in your plan account by
providing the administrator with written instructions, signed by all
registered holders.  You cannot sell any certificated shares that you may be
holding unless you first deposit them with the administrator pursuant to the
plan's share safekeeping service.

      Your sales will be made as soon as practicable after the administrator
receives written instructions from you.  Requests to sell plan shares will be
aggregated and processed within ten business days by an independent broker,
which is not an affiliate of ours, designated by the administrator on the
open market at prevailing market prices.  When you sell your shares, the
price per share that you will receive will be the average of the proceeds
from all shares sold by the administrator, less brokerage and administrative
fees (currently $0.075 per share), transfer taxes, if any, withholding tax,
if any, and a $15 service fee for the handling of each such request.

      You are required to maintain a balance of one or more full shares of
common stock or we may terminate your plan account.  We will treat a request
to sell all shares held in your account as a withdrawal from the plan.  See
"Our Termination of an Account" and "Withdrawal and Termination."

Custody of Stock and Issuance of Stock Certificates

      The administrator will hold all shares purchased on your behalf through
the plan in safekeeping in our name or the name of our nominee.  However, you
may at any time and without charge, obtain a certificate for all or part of
the whole shares credited to your plan account by making a request in writing
to the administrator.  We will not issue any certificates for fractional
shares.  Obtaining certificates for your plan account shares in no way
affects dividend reinvestment.  See "Dividend Reinvestment Options."


Share Safekeeping

      The plan's "share safekeeping" service allows you to deposit common
stock certificates held by you with the administrator for safekeeping.  The
advantages of the share safekeeping service are:


                                       9


0     The risk associated with the loss of your stock certificate(s) is
      eliminated.  If your certificates are lost or stolen, then you cannot
      sell or transfer your shares without first obtaining replacement
      certificates.  This process of replacing lost certificates could take
      several weeks and would result in cost and paperwork, both for you and
      for us.

0     Certificates deposited with the administrator will be transferred into
      our name or the name of our nominee and credited to your account under
      the plan.  The shares then will be treated in the same manner as shares
      purchased through the plan, and you may conveniently and efficiently
      sell or transfer those shares through the plan.  See "Sale of Common
      Stock," "Gift/Transfer of Shares Held in the Plan" and "Withdrawal and
      Termination."

0     You have all plan options available to you, including full or partial
      reinvestment and/or receiving dividends by check or electronic deposit.

      To participate in the plan's share safekeeping service, you must
complete and return an authorization form, along with the common stock
certificates you wish to deposit, to the administrator by registered and
insured mail.  You should not endorse the certificates or complete the
assignment section.  You may obtain an authorization form by calling or
writing the administrator.  If you have lost any of your certificates, then
you must replace them before you may participate in the share safekeeping
service.

Gift/Transfer of Shares Held in the Plan

      You may transfer the ownership of some or all of your plan shares,
including shares held in safekeeping, by mailing to the administrator a
properly executed stock assignment form, which you may obtain from the
administrator or a financial institution, with a Medallion Signature
Guarantee for all owners and a letter of instruction.  A Medallion Signature
Guarantee is a signature guarantee by an institution such as a commercial
bank, trust company, securities broker/dealer, credit union or a saving
institution participating in a Medallion Program approved by the Securities
Transfer Association, Inc.  You may transfer shares to new or existing
shareowners.

      Unless otherwise instructed, the administrator will retain the shares
and enroll the transferee in full dividend reinvestment, provided the
transferee is eligible to participate.  The new participant will receive a
statement showing the number of shares transferred and now held in his or her
plan account, which will be considered the transaction confirmation.

Withdrawal and Termination

      You may withdraw from the plan at any time by giving written notice to
the administrator.  If you terminate participation in the plan, all
reinvestment of your dividends will immediately stop if the notice of
withdrawal is received by the administrator not later than ten business days
prior to the record date for the next dividend payment.  Investment of
optional cash will stop immediately if notification of withdrawal from the
plan is received by the administrator at least two business days prior to the
applicable investment date.  The entire amount of any optional cash received
for which investment has been stopped by termination of participation in the
plan will be refunded to you without interest.

      Upon withdrawal from the plan, you or your personal representative or
other authorized agent may elect to either receive a certificate for the
number of whole shares held in your account and a check for the value of any
fractional share, or sell all shares in your account as described under "Sale
of Common Stock."

      If you terminate participation in the plan, then you will receive a
check for the cash value of any fractional share held in your plan accounts.
Fractions of shares will be valued at the then current market price,
determined in the same manner as provided with respect to the sale of whole
shares, less brokerage commissions, transfer taxes and withholding taxes, if
any.


                                       10



      You may not make any optional cash investments after you have terminated
participation in the plan unless and until you rejoin the plan, which you may
accomplish by complying with the enrollment procedures.  See "Enrollment
Procedures."  However, we reserve the right to reject any authorization form
from a previous participant on grounds of excessive joining and termination.
Such reservation is intended to minimize administrative expense and to
encourage use of the plan as a long-term investment service.

Stock Splits, Stock Dividends and Rights Offerings

      We will credit to your account any shares distributed pursuant to stock
dividends or stock splits effected by us on shares held by the administrator
for you.  If we make available to holders of our common stock subscription or
other rights to purchase additional shares of common stock or other
securities, then the administrator will, if and when the rights trade
independently, sell the rights accruing to all shares held by the
administrator for the participants and will apply the net proceeds of the
sale to the purchase of common stock.  However, we will, in advance of a
subscription offer, or, if the rights may not be independently traded upon
issuance, prior to the date on which the rights trade independently, inform
you that if you do not want the administrator to sell your rights and invest
the proceeds, then it will be necessary for you to transfer all full shares
held under the plan to your own name by a given date.  This would permit you
to exercise, transfer or sell the rights on the shares. If rights issued by
us are redeemed prior to the date that the rights trade independently, then
the administrator will invest the resultant funds in additional shares of
common stock.

Voting Rights

      The administrator will vote at shareowners' meetings any full shares of
common stock credited to your account under the plan in accordance with your
instructions.  The administrator will not vote such shares if you do not give
any instructions.  A proxy card will be mailed to you representing the shares
of common stock held in your plan account.

Fees and Charges

      No brokerage commissions, fees or service charges are charged to you in
connection with purchases of shares of common stock through the plan.  A
brokerage and administrative fee (currently $0.075 per share) and $15 service
fee is deducted from the proceeds of any sale of shares of common stock
through the plan.  The administrator also charges participants who reinvest
common stock dividends a fee of $0.50 per quarter to defray in part the
administrative costs of the plan.  The administrator reserves the right to
change these fees or charge participants other fees in the future.  Notices
of such future changes or additional fees will be sent to participants at
least 30 days prior to their effective date.  Any such change will be deemed
to be accepted by participants who do not terminate participation in the plan
prior to the effective date of the change.

Statements and Reports

      You will receive quarterly statements showing all transactions in your
account for that quarter, including the amount invested, the price paid per
share, the number of shares purchased and total shares accumulated.  You
should retain these statements for purposes of establishing the cost basis of
shares purchased under the plan for income tax and other purposes.

      In addition, you will receive copies of the same communications we send
to all other holders of common stock, including our annual reports, notices
of annual meetings and proxy statements, and information you need for
reporting dividend income for Federal income tax purposes.

      All notices, statements and reports to you will be addressed to you at
your last address we have on record.  Therefore, you must promptly notify us
by phone, in writing or through the internet of any change of address.



                                       11




No Right to Draw Against Account

      You will not have a right to draw checks or drafts against your account
or give instructions to the administrator with respect to any shares or cash
held therein, except as expressly provided in this prospectus.

Duties and Responsibilities

      Neither we nor any of our agents will have any responsibility beyond the
exercise of ordinary care for any action taken or omitted pursuant to the
plan, nor will we have any duties, responsibilities or liabilities, except as
expressly set forth in this prospectus.  Neither we nor any of our agents
will be liable under the plan for any act done in good faith or for any good
faith omission to act, including any claims of liability with respect to the
prices at which shares are purchased or sold for your account, the times when
the purchases or sales are made or any inability to purchase or sell shares,
for any fluctuation in the market value after purchase or sale of shares, or
arising out of failure to terminate your account upon your death prior to
receipt of notice in writing of your death.

      You should recognize that we cannot provide any assurance of profit or
protection against loss on any shares purchased under the plan.

Change or Termination of the Plan

      We reserve the right to amend, modify, suspend or terminate the plan in
whole, in part, or with respect to participants in one or more
jurisdictions.  We will send notice of any suspension, termination or
significant amendment, or modification of the plan to all affected
participants.  No such event will affect any shares then credited to a
participant's account.  Upon any whole or partial termination of the plan by
us, a certificate for whole shares credited to an affected participant's
account under the plan will be issued to the participant and a cash payment
will be made for any fraction of a share.  Fractions of shares will be valued
at the then current market price, determined in the same manner as provided
with respect to the sale of whole shares, less brokerage commissions,
transfer taxes and withholding tax, if any.  Any uninvested funds held by the
administrator at the time of any suspension or termination of the plan will
be remitted by the administrator to affected participants.

Our Termination of an Account

      We may terminate your enrollment in the plan if you no longer hold any
shares of record and your plan shares total less than one whole share of
common stock.  At our discretion we may also terminate your participation in
the plan upon written notice mailed to you at the address appearing on our
records.  Upon termination, you will receive a certificate for whole shares
held in your account and a check for the value of any fractional share held
in your plan account.  Fractions of shares will be valued at the then current
market price, determined in the same manner as provided with respect to the
sale of whole shares, less brokerage commissions, transfer taxes and
withholding tax, if any.

Interpretation of the Plan

      We may in our discretion interpret and regulate the plan as we deem
necessary or desirable in connection with the operation of the plan and
resolve questions or ambiguities concerning the various provisions of the
plan.

Governing Law

      The plan will be governed by the internal laws of the State of Wisconsin.

                      Federal Income Tax Consequences

      The following discussion sets forth the general Federal income tax
consequences for an individual participating in the plan.  This discussion is
not, however, intended to be an exhaustive treatment of the tax
consequences.  Future legislative changes or changes in administrative or
judicial interpretation, some or all of which may be retroactive, could
significantly alter the tax treatment discussed herein.  Accordingly, and
because 


                                       12



tax consequences may differ among participants in the plan, you
should consult your own tax advisor to determine the particular tax
consequences, including state income tax consequences, that may result from
participation in and the subsequent disposal of shares purchased under the
plan.
       

                  General Considerations

      In general, participants reinvesting dividends under the plan have the
same federal income tax consequences with respect to their dividends as do
shareowners who are not reinvesting dividends under the plan.  On the
dividend payment date, participants will receive a taxable dividend equal to
the cash dividend reinvested, to the extent we have earnings and profits.
This treatment applies with respect to both the shares of common stock held
of record by the participant and the participant's plan account shares even
though the dividend amount is not actually received in cash but is instead
applied to the purchase of shares of common stock for the participant's plan
account.  If shares are purchased on the open market or in a privately
negotiated transaction, then the participant's share of brokerage fees, if
any, that we pay will also be taxed as an additional dividend to that
participant, to the extent we have earnings and profits.

      Shares or any fractions of shares of common stock purchased on the open
market or in a privately negotiated transaction with reinvested dividends
will have a tax basis equal to the amount paid therefor, increased by any
brokerage fees treated as a dividend to the participant.  Shares or any
fractions of shares of common stock purchased from us with reinvested
dividends will have a tax basis equal to the amount of the dividend.  Whether
purchased on the open market or in a privately negotiated transaction or from
us, the shares or any fractions of shares will have a holding period
beginning on the day following the purchase date.

      Participants that make initial or optional cash investments under the
plan will be deemed to have received an additional taxable dividend in the
amount of the participant's pro rata share of the brokerage commissions, if
any, that we pay, to the extent we have earnings and profits.  Such brokerage
commissions will only be incurred on the purchase of the common stock in the
open market or in privately negotiated transactions.  Shares or any fractions
of shares purchased with initial or optional cash investments will have a tax
basis equal to the amount of the payments increased by the amount of
brokerage fees, if any, treated as a taxable dividend to the participant with
respect to those shares or fractions of shares.  The holding period for the
shares or fractions of shares will begin on the day following the purchase
date.

      Participants should not be treated as receiving an additional taxable
dividend based upon their pro rata share of the costs of administering the
plan which we pay.  However, we cannot provide any assurances that the
Internal Revenue Service will agree with this position.  We have no present
plans to seek formal advice from the IRS on this issue.

      Participants will not recognize taxable income when they receive
certificates for whole shares credited to their account, either upon their
request for the certificates or upon withdrawal from, or termination of the
plan.  However, participants will generally recognize gain or loss when
shares acquired under the plan are sold or exchanged either through the plan
at their request or by participants themselves after receipt of certificates
for shares from the plan.  Participants will also generally recognize gain or
loss when they receive cash payments for fractional shares credited to their
accounts, upon the sale of shares through the plan or upon withdrawal from or
termination of the plan.   The amount of gain or loss is the difference
between the amount which the participant receives for his or her whole shares
or fractional shares and the tax basis thereof.  Provided that the shares are
capital assets in the hands of the participant, the gain or loss will be a
capital gain or loss, long-term or short-term depending on the participant's
holding period.

Tax Withholding

      In the case of a participating foreign shareowner whose dividends are
subject to United States income tax withholding, or a participating domestic


                                       13




shareowner subject to backup withholding because a correct taxpayer
identification number has not been furnished or otherwise, the tax required
to be withheld will be deducted from the amount of any cash dividend
reinvested.  Since any withholding tax applies also to a dividend on shares
credited to the participant's plan account, only the net dividend on the
shares will be applied to the purchase of additional shares of common stock.
The regular statements sent to participants will indicate the amount of tax
withheld.  Likewise, participants selling shares through the plan who are
subject to backup or other withholding will receive only the net cash
proceeds from the sale as required by the Internal Revenue Code and the
Treasury Regulations thereunder. We cannot refund amounts withheld.
Participants subject to withholding should contact their tax advisors or the
IRS for additional information.

                    Rights to Purchase Common Stock

      We have entered into a rights agreement pursuant to which each
outstanding share of our common stock, including those shares that we are
selling pursuant to this prospectus, has attached a right to purchase
one-half of one share of our common stock.  A right will attach to each share
of our common stock we subsequently issue prior to the expiration of the
rights agreement.  Under circumstances described below, the rights will
entitle the holder of the rights to purchase additional shares of our common
stock.  In this prospectus, unless the context requires otherwise, all
references to our common stock include the accompanying rights.

      Currently, the rights are not exercisable and trade with our common
stock.  If the rights become exercisable, then each full right, unless held
by a person or group that beneficially owns more than 15% of our outstanding
common stock, will initially entitle the holder to purchase one half of one
share of our common stock at a purchase price of $95 per full share, or
$47.50 per half share, subject to adjustment.  The rights will become
exercisable only if a person or group has acquired, or announced an intention
to acquire, 15% or more of our outstanding common stock.  Under some
circumstances, including the existence of a 15% acquiring party, each holder
of a right, other than the acquiring party, will be entitled to purchase at
the right's then-current exercise price, shares of our common stock having a
market value of two times the exercise price.  If another corporation
acquires us after a party acquires 15% or more of our common stock, then each
holder of a right will be entitled to receive the acquiring corporation's
common shares having a market value of two times the exercise price.  The
rights may be redeemed at a price of $0.001 until a party acquires 15% or
more of our common stock and, after that time, may be exchanged for one share
of our common stock per right until a party acquires 50% or more of our
common stock.  The rights expire on January 20, 2009, subject to extension.
Under the rights agreement, our board of directors may reduce the thresholds
applicable to the rights from 15% to not less than 10%.  The rights do not
have voting or dividend rights and, until they become exercisable, have no
dilutive effect on our earnings.

                             Legal Matters

      The validity of the shares of common stock offered by this prospectus
will be passed upon for us by Foley & Lardner LLP, Milwaukee, Wisconsin.

                                  Experts

     The consolidated  financial  statements and the related financial statement
schedule  incorporated  in this  prospectus  by reference  from  Alliant  Energy
Corporation's  Annual  Report on Form 10-K for the year ended  December 31, 2003
have been audited by Deloitte & Touche LLP, independent auditors, as stated in 
their report,  which is incorporated herein by reference (which report expresses
an  unqualified  opinion and includes an explanatory  paragraph  relating to the
adoption of Statement of Financial Accounting Standards No. 143, "Accounting for
Asset Retirement  Obligations"),  and have been so incorporated in reliance upon
the report of such firm given upon their  authority as experts in accounting and
auditing.


                                       14




                      Where You Can Find More Information

      We file annual, quarterly and current reports, proxy statements and
other information with the SEC.  We have also filed registration statements
on Form S-3, including exhibits, under the Securities Act of 1933 with
respect to the common stock offered by this prospectus.  This prospectus is a
part of the registration statements, but does not contain all of the
information included in the registration statements or the exhibits.  You may
read and copy the registration statements and any other document that we file
at the SEC's public reference rooms at 450 Fifth Street, N.W., Washington
D.C.  You can call the SEC at 1-800-SEC-0330 for further information on the
operation of the public reference rooms.  You can also find our public
filings with the SEC on the internet at a web site maintained by the SEC
located at http://www.sec.gov.

      We are "incorporating by reference" specified documents that we file
with the SEC, which means:

0     incorporated documents are considered part of this prospectus;

0     we are disclosing important information to you by referring you to those
      documents; and

0     information we file with the SEC will automatically update and supersede
      information contained in this prospectus.


      This prospectus incorporates by reference the documents listed below
that we have previously filed with the SEC. They contain important
information about us and our financial condition.


SEC Filings (File No.1-9894)         Description or Period/As of Date
--------------------------------     --------------------------------
                              
Annual Report on Form 10-K           Year ended December 31, 2003
                       
Quarterly Reports                    Quarters ended 3/31/04, 6/30/04
on Form 10-Q                         and 9/30/04
                       
Current Reports on                   Dated 4/30/04,7/13/04,7/26/04,
Form 8-K                             7/27/04, 12/1/04,1/25/05 and
                                     2/4/05
                       
Registration Statement on            Description of our common
Form 8-B                             stock, dated April 1, 1988
                       
Registration Statement on            Description of our common share
Form 8-A                             purchase rights,dated January 20, 1999
                  

      We also incorporate by reference any future filings we make with the SEC
under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of
1934 after the date of this prospectus and before the end of the offering of
our common stock.  These documents include periodic reports, such as Annual
Reports on Form 10-K, Quarterly Reports on Form 10-Q, and Current Reports on
Form 8-K, as well as proxy statements.

      You can obtain any of the documents incorporated by reference in this
document from the SEC through the SEC's web site at the address provided
above.  We will provide to you documents incorporated by reference without
charge, upon your written or oral request, excluding any exhibits to those
documents unless the exhibit is specifically incorporated by reference as an
exhibit in this prospectus.  You can obtain documents incorporated by
reference in this prospectus by requesting them in writing or by telephone at
the following:

      Alliant Energy Corporation
      4902 North Biltmore Lane
      Madison, Wisconsin 53718
      Attention:  F. J. Buri
      Corporate Secretary
      Telephone: (608)458-3311


                                       15

                                    



                     ALLIANT ENERGY CORPORATION

                       SHAREOWNER DIRECT PLAN













                        ____________________


                             PROSPECTUS

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                          February 14, 2005