Abstract:RAPD analysis was adopted to identify Astragalus membranaceus Bge. and Astragalus membranaceus var. mongholicus(Bge.)Hsiao. With the method of BSA, 120 decamer random primers were used to amplify the DNA pools from A. membranaceus and A. membranaceuss var. mongholicus, and seven polymorphic primers were screened. Those polymorphic primers were used to detect the individual samples, a band of 300 bp from primer OPD14 was specifically amplified in the tested A. membranaceus and were absent in the tested A. membranaceuss var. mongholicus. This indicted that the band had specific character of A. membranaceus and marked as OPC14-300. SCAR marker was developed from the RAPD marker OPD14-300 by cloning, sequencing and designing one pair of primers and the SCAR marker only presented in the individuals of A. membranaceus, thus, it can be used to identify A. membranaceus and A. membranaceuss var. mongholicus at molecular level quickly and accurately.