Ownership Submission
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
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(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.
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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.

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