8-K

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

_________________

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of
the Securities Exchange Act of 1934

_________________

Date of Report
(Date of earliest
event reported):	August 31, 2007

Alliant Energy Corporation

(Exact name of registrant as specified in its charter)

Wisconsin	1-9894	39-1380265
(State or other	(Commission File	(IRS Employer
jurisdiction of	Number)	Identification No.)
incorporation)

4902 N. Biltmore Lane, Madison, Wisconsin 53718

(Address of principal executive offices, including zip code)

(608) 458-3311

(Registrant’s telephone number)

_________________

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

[   ] Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

[   ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

[   ] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

[   ] Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 5.04 Temporary Suspension of Trading Under Registrant’s Employee Benefit Plans.

        Alliant Energy Corporation (the “Company”) has advised participants in the Alliant Energy Corporation 401(k) Savings Plan (the “Plan”) that there will be a blackout period beginning on October 1, 2007 at 3:00 p.m. (Central Time) and ending during the calendar week beginning October 28, 2007, during which Plan participants will be unable to direct or diversify investments in their individual Plan accounts, change elections regarding future contributions or obtain any loan, withdrawal or distribution from the Plan. The blackout period is necessary for administrative reasons to implement a change in service provider for the Plan.

        The Company received notice from the administrator of the Plan of the impending blackout period (as required by Section 101(i)(2)(E) of the Employment Retirement Income Security Act of 1974, as amended) on August 31, 2007. On August 31, 2007, the Company sent a notice to its directors and executive officers informing them that a blackout period will be in effect beginning on October 1, 2007 at 3:00 p.m. (Central Time) and ending during the calendar week beginning October 28, 2007 and restricting them from purchasing, acquiring, selling or otherwise transferring common stock of the Company. A copy of the notice provided to the Company’s directors and executive officers is filed hereto as Exhibit 99.1 and incorporated by reference herein.

        The Company’s security holders and other interested persons may obtain, without charge, the actual beginning and ending dates of the blackout period by contacting F. J. Buri, the Company’s Corporate Secretary, 4902 N. Biltmore Lane, Madison, Wisconsin 53718, 608-458-5562.

Item 9.01. Financial Statements and Exhibits.

(a) Not applicable.

(b) Not applicable

(c) Not applicable.

(d) Exhibits. The following exhibit is being filed herewith:

(99.1) Notice of Blackout Period, dated August 31, 2007, to the Directors and Executive Officers of Alliant Energy Corporation.

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SIGNATURES

        Pursuant to the requirements of the Securities Exchange Act of 1934, Alliant Energy Corporation has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	ALLIANT ENERGY CORPORATION
Date: August 31, 2007
	By:  /s/ Thomas L. Hanson
	Thomas L. Hanson
	Vice President-Controller and
	Chief Accounting Officer

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EXHIBIT INDEX

Exhibit No. Description

(99.1) Notice of Blackout Period, dated August 31, 2007, to the Directors and Executive Officers of Alliant Energy Corporation.

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EX-99.1

NOTICE OF BLACKOUT PERIOD

To: Directors and Executive Officers of Alliant Energy Corporation

Re: Alliant Energy Corporation Blackout Period

Date: August 31, 2007

        This notice is to inform you, as directors and executive officers of Alliant Energy Corporation (the “Company”), that the Alliant Energy Corporation 401(k) Savings Plan (the “Plan”) will be subject to a “blackout period” during which Plan participants will be unable to direct or diversify investments in their individual Plan accounts, change elections regarding future contributions, obtain any loan, withdrawal or distribution from the Plan. The blackout period is necessary for administrative reasons to implement a change in service provider for the Plan.

        In addition, as described below, this blackout period will also prohibit you from purchasing, selling or transferring Alliant Energy Corporation common stock outside of the Plan, whether or not you are a participant in, or eligible to participate in, the Plan. The Plan blackout period is expected to begin on October 1, 2007 at 3:00 p.m. (Central Time) and end during the calendar week beginning October 28, 2007.

        In accordance with the Sarbanes-Oxley Act of 2002, the SEC’s Regulation BTR prohibits the Company’s directors and executive officers from directly or indirectly purchasing, selling or otherwise acquiring or transferring any shares of the Company’s common stock or other equity securities of the Company, including pursuant to options to acquire common stock and other derivative securities, during the Plan blackout period. This trading restriction bars directors and executive officers from trading within the Plan as well as trading outside the Plan. Again, the Plan blackout period, and thus the period in which you are prohibited from trading Company shares, is expected to begin on October 1, 2007 at 3:00 p.m. (Central Time) and end during the calendar week beginning October 28, 2007.

        The trading restriction during the Plan blackout period is subject to certain exceptions. However, given the complexity of these rules and the short time period involved, you are urged to avoid any discretionary change in your beneficial ownership of the Company’s common stock or other equity securities during the blackout period. Even if you think an exception applies to you, we ask that you not trade any Company security or derivative during the blackout period, unless you have advance written permission from F.J. Buri, the Company’s Corporate Secretary.

        If you have any questions concerning this notice, the blackout period or the transactions affected by the blackout period, then please contact F.J. Buri, the Company’s Corporate Secretary, 4902 N. Biltmore Lane, Madison, Wisconsin 53718, 608-458-5562. You may obtain, without charge, information as to whether the blackout period has begun or ended by contacting Mr. Buri at the address and phone number listed above.