SEC FORM 4

SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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

1. Name and Address of Reporting Person^*

GRIFFIN RANDALL M

(Last)

(First)

(Middle)

11666 FARSIDE ROAD

(Street)

ELLICOTT CITY

21042

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
CORPORATE OFFICE PROPERTIES TRUST [ OFC ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)	X	Other (specify below)
	President & CEO		Trustee

3. Date of Earliest Transaction (Month/Day/Year)
08/03/2009

4. If Amendment, Date of 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

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Shares	08/03/2009		M		53,300	A	$7.375	560,482⁽¹⁾	D
Common Shares	08/03/2009		S		53,300	D	$33.86	507,182⁽²⁾	D
Common Shares	08/04/2009		M		106,700	A	$7.375	613,882⁽⁴⁾	D
Common Shares	08/04/2009		S		106,700	D	$33.9	507,182⁽³⁾	D

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 Securities Underlying Derivative Security (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: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Options of Common Shares	$7.375	08/03/2009		M			53,300	12/16/2000	12/16/2009	Common Shares	53,300	$7.375	356,700	D
Options of Common Shares	$7.375	08/04/2009		M			106,700	12/16/2000	12/16/2009	Common Shares	106,700	$7.375	250,000	D

Explanation of Responses:

1. As of 8/3/09, common share holdings comprised of 95,888 owned by RMG Security Trust, 2,525 owned by spouse and daughters, 2,000 owned by Rand Griffin Non-qualified 401K plan, 299,086 unrestricted and 160,983 restricted.

2. As of 6/12/09, common share holdings comprised of 95,888 owned by RMG Security Trust, 2,525 owned by spouse and daughters, 2,000 owned by Rand Griffin Non-qualified 401K plan, 245,786 unrestricted and 160,983 restricted.

3. As of 8/4/09, common share holdings comprised of 95,888 owned by RMG Security Trust, 2,525 owned by spouse and daughters, 2,000 owned by Rand Griffin Non-qualified 401K plan, 245,786 unrestricted and 160,983 restricted.

4. As of 8/4/09, common share holdings comprised of 95,888 owned by RMG Security Trust, 2,525 owned by spouse and daughters, 2,000 owned by Rand Griffin Non-qualified 401K plan, 352,486 unrestricted and 160,983 restricted.

	Karen M. Singer, by Power of Attorney	08/04/2009
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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