Abstract: Tianhuafeng is a commonly used Chinese traditional drug. According to the hisitorical notes,its botanical origin is the root of Trichosanthes kirilowii Maxim. This paper deals with microscopical, physical and chemical methode of analysis applied to identify the roots of 7 species of the genus Trichosanthes namely T. kirilowii, T. crenulata, T. stylopodifera, T. sinopunctata, T. hupehensis,T. cucumeroides, T. cavaleriei, which were reported to be frequently used as Tianhuafeng. The characteristics for identification were found and most of them were illustrated or photographed. Based on this investigation, 20 samples of the commercial drug Tianhuafeng gathered from 18 provinces (cities or automonus regions) were identified.