Exhibit 21.1


                     CORPORATE OFFICE PROPERTIES TRUST
                        SUBSIDIARIES OF REGISTRANT

Delaware
      Corporate Office Properties, L.P.
      Corporate Office Properties Holdings, Inc.
      COPT Acquisitions, Inc.

Maryland 
      Airport Square II, LLC 
      Airport Square IV, LLC 
      Airport Square V, LLC
      Airport Square X, LLC 
      Airport Square XI, LLC 
      Airport Square XIII, LLC
      Airport Square XIV, LLC 
      Airport Square XIX, LLC 
      Airport Square XX, LLC
      Browns Wharf, LLC 
      COPT Brandon, LLC 
      Corporate Gatespring, LLC 
      Corporate Gatespring II, LLC 
      Gateway 44, LLC 
      Lakeview at the Greens, LLC 
      NBP One, LLC 
      NBP 131-133-141, LLC 
      NBP 134, LLC 
      NBP 135, LLC 
      St. Barnabus, LLC 
      Tech Park I, LLC 
      Tech Park II, LLC 
      Tech Park IV, LLC 
      Three Centre Park, LLC
      Tred Lightly, LLC 
      7200 Riverwood, LLC

New Jersey
      South Brunswick Investors, L.P.

Pennsylvania
      Blue Bell Investment Company, L.P.
      Comcourt Investors, L.P.
      6385 Flank Drive, L.P.