EXHIBIT 21.1 SUBSIDIARIES OF BIOMED REALTY TRUST, INC. AS OF DECEMBER 31, 2004: Jurisdiction of Formation/ Name Incorporation - ---- --------------- BioMed Realty, L.P. Maryland BioMed Realty Holdings, Inc. Maryland BioMed Realty LLC Delaware BMR-34790 Ardentech Court LLC Delaware BMR-8808 Balboa Avenue LLC California BMR-Bayshore Boulevard LLC Delaware BMR-6411 Beckley Street LLC Delaware Guilford Real Estate Trust 1998-1 Utah BMR-17190 Bernardo Center Drive LLC Delaware BMR-Bridgeview Technology Park LLC Delaware BMR-3030 Bunker Hill Street LLC Delaware BMR-2600 Eisenhower Road LLC Delaware BMR-201 Elliott Avenue LLC Delaware BMR-201 Industrial Road LLC Delaware BMR-145 King of Prussia Road GP LLC Delaware BMR-145 King of Prussia Road LP Delaware BMR-Landmark at Eastview LLC Delaware BMR-10165 McKellar Court GP LLC California 10165 McKellar Court LP California BMR-3450 Monte Villa Parkway LLC Delaware BMR-10255 Science Center Drive LLC Delaware BMR-9885 Towne Centre Drive LLC Delaware BMR-6611 Tributary Street LLC Maryland