Abstract:This paper, based on the morphological and phytogeographical characters, deals with origin, development and distribution of Crotalaria. Using analytical method of sectional and specific similarity, we have discussed the sharing and affinity relationship in the specific composition between Africa (included Madagascar) and India; India and its neibouring areas. And also the phytogeographical affinities of Crotalaria in Yunnan are discussed. The facts that the high similarity of specific composition showed between India and its neihouring areas(China 72%, Yunnan Province of this country 91%, Parkistan 90%, Indochina 88%, Indonesia(Java)84%)and that in these areas, the species are sharing with those of India except endemic species, suggest the species existed on the neibouring areas of India are probably distributed from India. The plants of Crotalaria are mostly distributed in S. and SE. Yunnan. By this distributive pattern, two dispersal lines are proposed. The first is the main one, i. e. from India→S.Burma→S. Yunnan (China); and the second is from NE. India→Centre of Burma→W. Yunnan(the region of Hengduan Mountains, Yunnan Tibet Border, China).