Abstract: The genus Stephania is one of the alkaloid-rich genus of the family Menispermaceae and includes about 50 species distributed in the whole world, among which approximately 32 species has been found in China, and 18 species are used medicinally.In this paper, 18 medicinal plant species in Stephania, their distritution, abundance of resources are reported, and the content of total alkaloid in each plant, the distribution of 17 alkaloids in root and tuberous root and the content of 10 alkaloids. are determined. The result of the present investigation revealed that plants of genus Stephania are abundant sources of isoquinoline types of alkaloids, especially those plants with tuberous roots from subgenus Shan-wu-gui are valuable raw materials for preparation of muscle relaxants. The result also provided some useful data for chemotaxonomy of Stephania genus.