Abstract: Bei-mu (贝母), the bulbs of some fritillaries, is one of the most popular drugs used in China ever since the ancient times. It is prescribed principally in coughs and fevers. In recent years, although much chemical and pharmaceutical investigations of this drug have been made, its botanical origin remains confused. Several types of commercial drugs Bei-mu, for instance, were incorrectly considered by some authers as being derived from the bolbs of Fritillaria roylei Hook., a species of Kashmir and Kumaon, not yet found in China. In the present paper, the writers attempt to give a revision of the genus Fritillaria of China as well as of commercial drugs sold on the chinese market under the name of Bei-mu, based on both plant and drug specimens collected from 18 provinces and autonomous regions. As a result of our study, twenty species, including two varieties, of Fritillaria of China are recognized, of which four, F. crassicaulis S. C. Chen, F. omeiensis S. C. Chen, F. unibracteata Hsiao et K. C. Hsia and F. hupehensis Hsiao et K. C. Hsia, and one variety, P. thunbergii Miq. var. chekiangensis Hsiao et K. C. Hsia, are described as new. They all, except two species, viz. F. maximowiczii Freyn and F. davidii Franch., are known to possess medicinal value, from which different kinds of commercial drugs Bei-mu are derived. These drugs are usually named for the places where they come from. The first, called Zhe-bei (浙贝), F. thunbergii Miq., is obtained from Chekiang and Kiangsu, the second, called Ping-bei (平贝), F. ussuriensis Maxim., from northeastern China, the third, called Lu-bei (炉贝), F. delavayi Franch., from southwestern China, the fourth, called Chuan-bei (川贝), including F. cirrhosa D. Don, F. unibracteata Hsiao et K. C. Hsia, F. przewalskii Maxim. etc., from Szechuan and its neighbouring provinces, and the fifth, called Yi-bei (伊贝), including F. pallidiflora Schrenk, F. karelinii (Fisch.) Baker, F. walujewii Rgl. etc., from Sinkiang. Occasionally, the tubers of Bolbostemma paniculatum (Maxim.) Franquet, the corms of Iphigenia indica Kunth and the bulbs of Lloydia tibetica Baker and Cyanotis vaga (Lour.) Roem. et Schult. are also called Bei-mu in some local drug markets. They are different not only in medicinal property but also in appearance from our traditional genuine commercial drugs Bei-mu as stated above. They are apparently adulterants. Detailed accounts about the plants and drugs are given in the text. There are also provided keys and illustrations which, we believe, will afford facilities for identification.