The terrestrial portion of Euphorbia watanabei MAKINO was found to contain, besides nonacosane (?), tetracosanol, a wax-like, m.p. 59∼60°, and β-sitosterol, five-membered ring triterpenes taraxerol acetate, lupeol acetate, alunusenone (?), taraxerone, luperone, and taraxasterol. It is interesting from botanical aspects that euphane series triterpenes, which would be anticipated from Euphorbia spp., were not obtained.