COPT Defense Properties (CDP) 8-K Other Events

Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration Statements on Form S-3 (No. 333-59766, 333-36740, 333-60379, 333-85210, No. 333-108785 and 333-132958) and Form S-8 (No. 333-87384, No. 333-88711, No. 333-111736, No. 333-118096 and No. 333-118097) of Corporate Office Properties Trust  of our report dated March 16, 2006, except with respect to our opinion on the consolidated financial statements insofar as it relates to the effects of the discontinued operations as discussed in Note 18, as to which the date is August 31, 2006, relating to the consolidated financial statements, financial statement schedule, management’s assessment of the effectiveness of internal control over financial reporting and the effectiveness of internal control over financial reporting, which appears in this Current Report on Form 8-K.

/s/ PricewaterhouseCoopers LLP

Baltimore, Maryland

August 31, 2006