Three kinds of Bupleuri Radix were found in Taiwan. To clarify their origins, histological studies were carried out to identify their internal and external structures. It was found that Bupleuri Radix or "Chai-hu" of Taiwan is derived from roots of the following species" 1, Bupleurum chinense which was imported from China, 2, Bupleurum falcatum var. komarowi a cultivated production of Japanese origin, and 3, Bupleurum kaoi which is indigenous to Taiwan. These Bupleuri Radix were easily assigned by anatomical characteristics and their qualitative analysis of active principle - saikosaponin were established by TLC.