Abstract:This paper reports two sesquiterpene alkaloids isolated from Tripterygium wilfordii Hook. f. Their structures are assigned as Ⅰ and Ⅱ, respectively, by MS, UV, IR, 1HNMR and 13CNMR spectroscopic analysis. Alkaloid Ⅱ is a new alkaloid named wilfornine. These al- kaloids were shown to be immunosuppressives.