Molecular characterizations of Astragalus L.species can elucidate the relationships among the species and provide more information about the taxonomy of this valuable genus.In this study,the genetic relationships among 45 Astragalus accessions from Mongolian Plateau and its surrounding areas were analyzed using inter-simple sequence repeat (ISSR) primers.11 selected ISSR primers generated a total of 188 valid loci,of which 178 exhibited polymorphisms.Unweighted pair-group method of cluster analysis based on dice similarity values separated the accessions into seven groups.Seven species were recognized within these groups.A.koburensis was placed in the same group as A.galactites accessions,showing that this species was only variants or ecotype of A.galactites.Pedicel variants of A.scaberrimus and pod variants of A.variabilis were also been detected by forming distinct subgroups within the clusters of these species.A.leansanicus was separated from A.limprichtii.The grouping of accessions was generally consistent with principal coordinate analysis (PCoA) and the results showed that it was reasonable to organize the species of Astragalus at section level,but some sections and the affiliation of some species should be modified.Application of multiple DNA marker systems and more samples from different species will help to reveal more accurately the phylogenetic relationships among Astragalus species.