Two kinds of the Chinese drug, Pai-pu, obtained from the local market were subjected to an experiment. One of them has been identified to be Stemona sessilifolia, and the other not ascertained yet. However, a known alkaloid, tuberostemonine, has been isolated from the latter, which, therefore, is likely to belong to Stemona tuberosa. It has been found that the base of this alkaloid can be easily seperated from the mixture in the form of a crystalline hydriodide with a melting point of 2520, and further comfirmed by analyses of its crystalline salts: perchlorate, m.p. 242° and methiodide, m.p. 236°.