Chromatographic separation of the stem bark extract of Mitragyna stipulosa afforded triterpene derivatives ursolic acid (1), quinovic acid (2), quinivic acid 3-O-beta-D-glucopyranoside (3, quinovin glycoside C), quinovic acid 3-O-[(2-O-sulfo)-beta-D-quinovopyranoside] (4, zygophyloside D) and quinovic acid 3-O-beta-D-quinovopyranosyl-27-O-beta-D-glucopyranosyl ester (5, zygophyloside B). These five compounds were subjected to the cytotoxicity on MTT assay system. Compound 1 among tested showed the most potent cytotoxicity. Quinovic acid showed less potent cytotoxicity than ursolic acid and sugar linkages to 2 decreased the cytotoxicity. Compound 4 more potent than 3 with indicate that the sulfonyl group significantly enhances the activity. This indicates that the glycosidic linkage in ursane-type triterpenoids has mainly negative effect on cytotoxicity unlike in oleanane-type glycosides.