Biomed Realty Trust POSASR Automatic shelf registration (post-effective amendment)

Exhibit 12.1

Statement of Computation of Ratios

BioMed Realty Trust, Inc.

	Nine Months Ended			Year Ended December 31,
	September 30, 2010			2009			2008			2007			2006			2005
Earnings:
Add:
Income from continuing operations before minority interests and income/loss from unconsolidated joint ventures	$	27,060		$	62,580		$	64,331		$	73,099		$	34,745		$	17,877
Amortization of interest capitalized		3,327			3,009			1,307			59			43			20
Distributions from unconsolidated joint ventures		1,195			586			687			357			130			106
Fixed charges (see below)		68,855			77,403			83,492			86,918			48,742			23,934
Subtract:
Interest capitalized		(4,136	)		(12,405	)		(42,320	)		(58,132	)		(7,797	)		(708	)
Total earnings	$	96,301		$	131,173		$	107,497		$	102,301		$	75,863		$	41,229
Fixed charges:
Interest expensed		64,719			64,998			41,172			28,786			40,945			23,226
Interest capitalized		4,136			12,405			42,320			58,132			7,797			708
Total fixed charges	$	68,855		$	77,403		$	83,492		$	86,918		$	48,742		$	23,934
Ratio of earnings to fixed charges		1.4			1.7			1.3			1.2			1.6			1.7
Ratio of earnings to fixed charges and preferred stock dividends		1.2			1.4			1.1			1.0			1.6			1.7
Preferred stock dividends	$	12,722		$	16,963		$	16,963		$	16,868		$	—		$	—

BioMed Realty L.P.

	Nine Months Ended			Year Ended December 31,
	September 30, 2010			2009			2008			2007			2006			2005
Earnings:
Add:
Income from continuing operations before minority interests and income/loss from unconsolidated joint ventures	$	27,060		$	62,580		$	64,331		$	73,099		$	34,745		$	17,877
Amortization of interest capitalized		3,327			3,009			1,307			59			43			20
Distributions from unconsolidated joint ventures		1,195			586			687			357			130			106
Fixed charges (see below)		68,855			77,403			83,492			86,918			48,742			23,934
Subtract:
Interest capitalized		(4,136	)		(12,405	)		(42,320	)		(58,132	)		(7,797	)		(708	)
Total earnings	$	96,301		$	131,173		$	107,497		$	102,301		$	75,863		$	41,229
Fixed charges:
Interest expensed		64,719			64,998			41,172			28,786			40,945			23,226
Interest capitalized		4,136			12,405			42,320			58,132			7,797			708
Total fixed charges	$	68,855		$	77,403		$	83,492		$	86,918		$	48,742		$	23,934
Ratio of earnings to fixed charges		1.4			1.7			1.3			1.2			1.6			1.7
Ratio of earnings to fixed charges and preferred unit distributions		1.2			1.4			1.1			1.0			1.6			1.7
Preferred unit distributions	$	12,722		$	16,963		$	16,963		$	16,868		$	—		$	—