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 * ARMSTRONG WALLY   2. Issuer Name and Ticker or Trading Symbol ENTERPRISE BANCORP INC /MA/ [EBTC] 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) C/O ENTERPRISE BANCORP INC, 222 MERRIMACK STREET 3. Date of Earliest Transaction (Month/Day/Year) 12/28/2005 (Street) LOWELL, MA 01852 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 12/28/2005   S   0.7083 D $ 33.26 76,476.2083 (1) D   Common Stock 01/26/2006   S   3,500 D $ 30.52 72,976.2083 D   Common Stock 06/09/2006   S   497 D $ 32.0159 72,483.8735 (2) D   Common Stock 06/12/2006   S   100 D $ 32.25 72,383.8735 D   Common Stock 06/12/2006   S   900 D $ 32 71,483.8735 D   Common Stock 11/02/2006   S   3,000 D $ 15.4783 139,972.4196 (3) (4) D   Common Stock 11/03/2006   S   1,000 D $ 15.49 138,972.4196 D

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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

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
ARMSTRONG WALLY C/O ENTERPRISE BANCORP INC 222 MERRIMACK STREET LOWELL, MA 01852	X

Signatures

/s/ George L. Duncan as attorney-in-fact		11/06/2006
**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)	Includes 219.5935 shares of Common Stock acquired under the EBTC dividend reinvestment plan.
(2)	Includes 4.6652 shares of Common Stock acquired under the EBTC dividend reinvestment plan.
(3)	Includes 4.6726 shares of Common Stock acquired under the EBTC dividend reinvestment plan.
(4)	Reflects additional 71,483.8735 shares of EBTC stock which reporting person received on June 30, 2006 when the stock of EBTC split 2-for-1.

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