Exhibit



			Exhibit 21.1
CORPORATE OFFICE PROPERTIES TRUST
SUBSIDIARIES OF REGISTRANT

Alabama
COPT Bridge Street Office, LLC

Colorado
Colorado Land Acquisition, LLC
COPT Academy Ridge, LLC
COPT Aerotech, LLC
COPT Cresterra 3535, LLC
COPT Cresterra Master LLC
COPT Interquest, LLC
COPT Interquest III, LLC
COPT Interquest IV, LLC
COPT Interquest Epic I, LLC
COPT Interquest Hybrid I, LLC
COPT Interquest Hybrid II, LLC
COPT Newport C, LLC
COPT Newport D, LLC
COPT Northcreek, LLC
COPT Patriot Park at Galley, LLC
COPT Patriot Park I, LLC
COPT Patriot Park II, LLC
COPT Patriot Park V, LLC
COPT Patriot Park VI, LLC
COPT Patriot Park VII, LLC
Patriot Park, LLC

Delaware
Airport Square Holdings I, LLC
Airport Square Holdings VI and VII, LLC
Blue Bell Investment Company, LP
COPT Acquisitions, Inc.
COPT Colgate General, LLC
COPT Concourse, LLC
COPT DC-6, LLC
COPT Gateway Commerce, LLC
COPT Maritime I & II, LLC
COPT Stevens Place, LLC
Corporate Office Properties, LP
Corporate Office Properties Holdings, Inc.
Delaware Airport III, LLC
Delaware Airport VIII, LLC
Delaware Airport IX, LLC
Great Mills I, L.L.C.
Great Mills II, L.L.C.
Great Mills III, L.L.C.
Great Mills IV, L.L.C.
Great Mills V, L.L.C.
LW Redstone Company, LLC
Powerloft Holdings, LLC



7200 Riverwood, LLC
7205 Riverwood, LLC
7240 Parkway Drive Enterprises, LLC
7318 Parkway Drive Enterprises, LLC
7320 Parkway Drive Enterprises, LLC
7320 PD, LLC
7740 Milestone LLC
7760 Milestone Parkway, LLC
7780 Milestone Parkway, LLC
7874 Milestone Parkway, LLC
7876 Milestone Parkway, LLC
7878 Milestone Parkway, LLC
7880 Milestone Parkway, LLC
8027 Corporate Drive Business Trust
8621 RFD, LLC
8661 RFD, LLC
9690 Deereco Road, LLC
Airport Square II, LLC
Airport Square IV, LLC
Airport Square Partners, LLC
Airport Square Storms, LLC
Airport Square V, LLC
Airport Square XI, LLC
Airport Square XIII, LLC
Airport Square XXII, LLC
Airport Square, LLC
AP#5 Lot A, LLC
AP#5 Lot B, LLC
AP#5 Lot C, LLC
Arundel Preserve #5, LLC
ASI, LLC
Atrium Building, LLC
Campbell Boulevard I Business Trust
Campbell Boulevard II Business Trust
Campbell Boulevard Trust
Campbell Corporate Center 1-2 Business Trust
Canton Crossing Retail, LLC
Clarks Hundred II, LLC
Clarks Hundred, LLC
Columbia Equity Finance, LLC
Columbia Gateway S-28, LLC
COMI Investments LLC
Commons Office 6-B, LLC
Commons Office Research, LLC
Concourse 1304, LLC
COPT Aberdeen, LLC
COPT Arundel Preserve, LLC
COPT AP 9, LLC
COPT Babcock Business Trust
COPT Baltimore County I, LLC
COPT Baltimore County II, LLC
COPT Brock Bridge, LLC
COPT CC 1600, LLC
COPT CC Bulkhead LLC



COPT CC D1 LLC
COPT CC Holding LLC
COPT CC Parking LLC
COPT CC Tower LLC
COPT CCW I LLC
COPT CCW II LLC
COPT CCW III LLC
COPT Chantilly I Manager, LLC
COPT Chantilly II Manager, LLC
COPT Data Management, LLC
COPT Development & Construction Services, LLC
COPT Frederick, LLC
COPT Gate 63, LLC
COPT Gate 6700-6708-6724, LLC
COPT General, LLC
COPT Harbour's Edge LLC
COPT Harrisburg GP, LLC
COPT Harrisburg L.P.
COPT Huntsville, LLC
COPT Northgate A, LLC
COPT Northgate B, LLC
COPT Northgate C, LLC
COPT Northgate D, LLC
COPT Northgate H, LLC
COPT Northgate I, LLC
COPT Powerhouse LLC
COPT Pres Investment, LLC
COPT Property Management Services, LLC
COPT Renovation, LLC
COPT Riverwood, LLC
COPT T-11, LLC
COPT Virtru, LLC
COPT-Kirk AP#5, LLC
Cornucopia Holdings II, LLC
Cornucopia Holdings, LLC
Corporate Center I Limited Partnership
Corporate Center I, LLC
Corporate Development Services, LLC
Corporate Gatespring II, LLC
Corporate Gatespring, LLC
Corporate Office Management, Inc.
Corporate Office Services, LLC
Corporate Paragon, LLC
Corporate Place B Equity Affiliates, LLC
Corporate Place I Business Trust
Corporate Place III Business Trust
Corporate Place IV Business Trust
Corporate Property, LLC
Enterprise Campus Developer, LLC
Fifth Exploration, L.L.C.
Fourth Exploration, L.L.C.
Franklin Ridge No. 1 Business Trust
Franklin Ridge No. 2 Business Trust
Franklin Ridge No. 3 Business Trust



Franklin Ridge No. 4 Business Trust
Franklin Ridge Open Space Business Trust
Franklin Ridge V Business Trust
Gateway 44, LLC
Gateway 67, LLC
Gateway 70 Holdings, LLC
Gateway 70, LLC
Gateway Crossing 95, LLC
Honeyland 108, LLC
Huntsville Holdings, LLC
Jolly COPT I, LLC
Jolly COPT II, LLC
Lot 401 Business Trust
M Square 5825, LLC
M Square 5850, LLC
M Square Associates, LLC
M Square NOAA, LLC
Maritime Holdings, LLC
McLean Ridge I Business Trust
McLean Ridge II Business Trust
McLean Ridge III Business Trust
McLean Ridge IV Business Trust
MOR Forbes, LLC
NBP 131, LLC
NBP 132, LLC
NBP 133 LLC
NBP 134, LLC
NBP 135, LLC
NBP 140, LLC
NBP 141, LLC
NBP 191, LLC
NBP 201 Holdings, LLC
NBP 201, LLC
NBP 211 Holdings, LLC
NBP 211, LLC
NBP 220 Holdings, LLC
NBP 220, LLC
NBP 221, LLC
NBP 300 Restaurant, LLC
NBP 300, LLC
NBP 302, LLC
NBP 304, LLC
NBP 306, LLC
NBP 308, LLC
NBP 310, LLC
NBP 312 LLC
NBP 314, LLC
NBP 316, LLC
NBP 318, LLC
NBP 320, LLC
NBP 322, LLC
NBP 324, LLC
NBP 410, LLC
NBP 420, LLC



NBP 430, LLC
NBP 520, LLC
NBP 540, LLC
NBP Huff & Puff, LLC
NBP Lot 3-A, LLC
NBP One, LLC
NBP Retail, LLC
Nottingham Commons I Holding Corp.
Nottingham Commons II Holding Corp.
Nottingham Ridge Holding Corporation
Nottingham Ridge I Business Trust
Nottingham Ridge II Business Trust
Nottingham Ridge III Business Trust
Nottingham Ridge No. 20 Business Trust
Nottingham Ridge No. 30 Business Trust
One Sellner Road LLC
Park Circle Equities, LLC
Pecan Court, L.L.C.
Philadelphia Road Business Trust
Red Cedar Building, LLC
RG 2100 Restaurant, LLC
RIVA Trustee, LLC
Riverwood Business Center Equity Affiliates, LLC
Third Exploration, L.L.C.
Tyler Ridge I Business Trust
Tyler Ridge I, LLC
Tyler Ridge II A Business Trust
Tyler Ridge II Business Trust
Tyler Ridge Limited Partnership
Tyler Ridge Water Management Business Trust
W&M Business Trust
White Marsh Business Center 2 Business Trust
White Marsh Business Center Limited Partnership
White Marsh Business Center, LLC
White Marsh Hi-Tech 1 Business Trust
White Marsh Hi-Tech 2 Business Trust
WMBC 13A Investment Company, LLC

Pennsylvania
Colgatedrive Associates, L.P.
COPT Pennlyn, L.P.

Texas
COPT 8000 Potranco, L.P.
COPT 8030 Potranco, L.P.
COPT 8100 Potranco, L.P.
COPT San Antonio General, LLC
COPT San Antonio, LP
COPT San Antonio II, L.P.
COPT SA Technology Center, L.P.
COPT Sentry Gateway 100 LP
COPT Westpointe 3A, L.P.
COPT Westpointe 4, L.P.