Described herein are compounds that are antagonists of PGD2receptors. Also described are pharmaceutical compositions that include the compounds described herein, and methods of using such antagonists of PGD2receptors, alone or in combination with other compounds, for treating respiratory, cardiovascular, and other PGD2-dependent or PGD2-mediated conditions or diseases.本發明描述作為PGD2受體拮抗劑之化合物。本發明亦描述包括本文所述之化合物之醫藥組合物,以及單獨或與其它化合物組合使用該等PGD2受體拮抗劑治療呼吸、心血管及其它PGD2依賴性或PGD2介導之病狀或疾病之方法。