The legume species within the genus Hedysarum are deep-rooted annual or perennial herbs, and they are well distributed in the temperate zones. About 40 species of Hedysarum are native to China and they are potential foliages and are used as resources of herbal medicine. These legumes are pioneers plants, but its geographic distribution may be determined by the existence of proper rhizobia. Aiming at understanding the diversity of rhizobia associated with them, we isolated thirty rhizobial strains from root ...