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 report): December 23, 2004

ARGON ST, INC. (Exact Name of Registrant as specified in its charter)

DELAWARE
(State or other jurisdiction of incorporation)

000-08193	38-1873250
(Commission File No.)	(I.R.S. Employer Identification No.)

12701 Fair Lakes Circle, Suite 800, Fairfax, Virginia 22033 (Address of principal executive offices and zip code)

Registrant’s telephone number, including area code: (703)322-0881

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 (see General Instruction A.2. below):

     [   ] 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 14-d-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))

ARGON ST, INC. AND SUBSIDIARIES

ITEM 5.04 TEMPORARY SUSPENSION OF TRADING UNDER REGISTRANT’S EMPLOYEE BENEFIT PLANS

On December 23, 2004, ARGON ST, Inc. (the “Company”) sent a notice to its directors and Section 16 officers notifying them of a blackout period with respect to the ARGON ST, Inc. 401(k) Savings Plan. The blackout period is expected to begin January 24, 2005 and end February 25, 2005. The Company provided the notice to the directors and officers in accordance with Section 306 of the Sarbanes-Oxley Act of 2002 and Rule 104 of Regulation BTR. A copy of the notice is attached as Exhibit 99.1 hereto and is incorporated herein by reference.

ITEM 9.01 Financial Statements and Exhibits

(c) Exhibits

Exhibit Number	Description
99.1	Notice of Blackout Period to Directors and Section 16 Officers of ARGON ST, Inc. dated December 23, 2004.

SIGNATURES

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

	ARGON ST, INC.
December 23, 2004	By:	/s/ Donald F. Fultz
		Donald F. Fultz
		Chief Financial Officer

EXHIBIT INDEX

Exhibit Number	Description
99.1	Notice of Blackout Period to Directors and Executive Officers of ARGON ST, Inc. dated December 23, 2004

EX-99.1

EXHIBIT 99.1

December 23, 2004

To:	Directors and Section 16 Officers of Argon ST, Inc.
From:	Donald Fultz, CFO
Subject:	This notice is required pursuant to the Sarbanes-Oxley Act

This is to notify you of an upcoming blackout period under the Argon ST, Inc. (“Argon ST”) 401(k) plan. During this trading blackout, your ability to conduct transactions in Argon ST Equity Securities will be limited. We expect the blackout period to begin January 24, 2005 and end February 25, 2005.

The blackout period will allow the Company to replace the Sensytech 401(k) plan administered by Merrill Lynch with the Argon ST 401(k) plan administered by Fidelity. During the blackout period, participants will be unable to direct investments or change the assets held in their plan accounts or obtain a loan, withdrawal, or distribution from the 401(k) plan. Participants have been notified of the blackout period as of the date of this letter.

In addition, because the Sensytech plan offers Argon ST common stock as an investment option, pursuant to Section 306 of the Sarbanes-Oxley Act of 2002 Argon ST directors and Section 16 officers are not permitted to trade in Argon ST equity securities while the 401(k) participants are unable to complete transactions in the 401(k) plan.

Gifts and trading pursuant to a previously established 10b5-1 trading plan are exempt from this prohibition.

This notice is in addition to any other normal trading restrictions contained in Argon ST Policy.

If you have any questions, please do not hesitate to contact me at (703) 995-5695.

12701 Fair Lakes Circle Fairfax Virginia 22033 TEL 703-322-0881 FAX 703-322-0885 www.argonst.com