Nematocyphol is triterpene constituents from Euphorbia nematocypha Hand-Mazz. Seven triterpenoids have been isolated from the roots of Euphorbia nematocypha Hand-Mazz. through chromatography on 20% AgNO3-silica gel. One of them was identified as a new compound named nematocyphol on the basis of spectral data (IR, EIMS, 1H-NMR and 13C-NMR). Its structure was deduced as IVa. Other compounds were identified as nepehinol acetate (I), germanicol acetate (II), euphol (III), tanaxastanol (Va), 24-methylenecycloartanol (VIa) and nepehinol (VIIa). These compounds were obtained for the first time from this plant.