Abstract: 〗The structures of ursolic acid and oleanolic acid related compound，including natural products and synthetic derivatives of ursolic acid and oleanolic acid，were identified by physical and spectral analyses，or literature data.The inhibitory activity of the triterpene compounds against α-glycosidase were evaluated.The in vitro results showed that the test pentacyclic triterpenes exhibited diverse inhibitory activity against α-glycosidase.Within this series of compounds， 1a and 1b had better inhibitory activity than that of the others.It is possible that highly active compounds with α-glycosidase inhibition activity would be found through structural modification of pentacyclic triterpenes.