EXHIBIT 12.1

BOSTON PROPERTIES, INC.

CALCULATION OF RATIOS OF EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED DISTRIBUTIONS

Boston Properties, Inc.’s ratios of earnings to combined fixed charges and preferred distributions for the five years ended December 31, 2005 were as follows:

	Year Ended December 31,
	2005			2004			2003			2002			2001
	(dollars in thousands)
Earnings:
Add:
Income before minority interests in property partnerships, income from unconsolidated joint ventures, minority interest in Operating Partnership, gains on sales of real estate and other assets, discontinued operations, cumulative effect of a change in accounting principle and preferred dividend	$	304,324		$	304,864		$	288,475		$	263,625		$	231,056
Gains on sales of real estate and other assets		182,542			9,822			70,244			232,304			11,238
Amortization of interest capitalized		3,298			2,845			2,640			2,526			950
Distributions from unconsolidated joint ventures		7,179			6,663			8,412			8,692			2,735
Combined fixed charges and preferred distributions (see below)		340,589			334,082			342,244			316,835			306,709
Subtract:
Interest capitalized		(5,718	)		(10,849	)		(19,200	)		(22,510	)		(59,292	)
Preferred distributions		(26,780	)		(17,063	)		(23,608	)		(31,258	)		(36,026	)
Total earnings	$	805,434		$	630,364		$	669,207		$	770,214		$	457,370
Combined fixed charges and preferred distributions:
Interest expensed	$	308,091		$	306,170		$	299,436		$	263,067		$	211,391
Interest capitalized		5,718			10,849			19,200			22,510			59,292
Preferred distributions		26,780			17,063			23,608			31,258			36,026
Total combined fixed charges and preferred distributions	$	340,589		$	334,082		$	342,244		$	316,835		$	306,709
Ratio of earnings to combined fixed charges and preferred distributions		2.36			1.89			1.96			2.43			1.49

The ratio of earnings to combined fixed charges and preferred distributions was computed by dividing earnings by combined fixed charges and preferred distributions. Earnings consist of income before minority interests in property partnerships, income from unconsolidated joint ventures, minority interest in Operating Partnership, discontinued operations, cumulative effect of a change in accounting principle and preferred dividend, plus amortization of interest capitalized, distributions from unconsolidated joint ventures, and combined fixed charges and preferred distributions, minus interest capitalized and preferred distributions. Combined fixed charges and preferred distributions consist of interest expensed, which includes credit enhancement fees and amortization of loan costs, interest capitalized, and preferred distributions.