FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: January 31, 2005 Estimated average burden hours per response... 0.5

(Print or Type Responses)

1. Name and Address of Reporting Person * HARRISON DONALD C   2. Issuer Name and Ticker or Trading Symbol AtriCure, Inc. [ATRC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 525 UNIVERSITY AVENUE, SUITE 1400 3. Date of Earliest Transaction (Month/Day/Year) 08/10/2006 (Street) PALO ALTO, CA 94301 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 08/10/2006   X   788 (1) A $ 5.96 194,079 D   Common Stock 08/10/2006   X   788 D $ 5.96 738,417 I Held by Charter Ventures IV Partners, LLC (2) Common Stock 08/10/2006   X   788 D $ 5.96 8,713 I Held by Charter Advisors Fund IV, L.P. (3) Common Stock 08/10/2006   X   788 D $ 5.96 27,399 I Held by Charter Entrepreneures Fund IV, L.P. (4) Common Stock 08/10/2006   X   788 D $ 5.96 702,305 I Held by Charter Ventures IV, L.P. (5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
	Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.		SEC 1474 (9-02)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Common Stock Warrants (Right to Buy)

$ 5.43

08/10/2006

X

8,810

04/22/2002

08/10/2006

Common Stock

788 (6)

(7)

0

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
HARRISON DONALD C 525 UNIVERSITY AVENUE, SUITE 1400 PALO ALTO, CA 94301	X

Signatures

/s/ Thomas J. Etergino as Attorney-in-Fact for Donald C. Harrison		08/14/2006
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	On August 10, 2006, 8,810 warrants owned by Dr. Harrison were automatically exercised pursuant to a net issue exercise, resulting in his acquisition of 788 shares of Common Stock. The warrants were exercisable at $5.96 per share (a price equal to the closing average of the Common Stock for the 10 trading days prior to August 10, 2006).
(2)	Dr. Harrison disclaims beneficial ownership of the securities held by this entity, except as to his pecuniary interest therein.
(3)	Dr. Harrison disclaims beneficial ownership of the securities held by this entity, except as to his pecuniary interest therein.
(4)	Dr. Harrison disclaims beneficial ownership of the securities held by this entity, except as to his pecuniary interest therein.
(5)	Dr. Harrison disclaims beneficial ownership of the securities held by this entity, except as to his pecuniary interest therein.
(6)	The net number of shares of Common Stock issuable upon the exercise of 8,810 warrants, calculated pursuant to the terms of the warrant.
(7)	Not applicable.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.