Two new clerodane-type diterpenes, tinosporins C ( 1) and tinosporins D ( 2) were isolated from the stems of Tinospora sagittata (Oliv.), together with three known ones, columbin ( 3), tinophylloloside ( 4), and tinospinoside D ( 5). The structures of these compounds were determined on the basis of spectroscopic data interpretation, with that of the absolute configuration of compound 1 was assigned by experimental and calculated ECD spectra. The cytotoxicity and α-glucosidase inhibitory activities of isolated compounds were evaluated in vitro.