Abstract: To clarify the interspecies difference of Astragalus has an important impact on its industrial planting,the differences between Astragalus mongolicus and A. membranaceus were analyzed including root structure development,root morphology,medicinal components and apparent growth respectively. The results showed that:（1） On the early stage,there was no significant difference in root structure between Astragalus species,while sowing 60 d later,starch accumulation in phloem ray and xylem ray parenchyma cells of A. mongolicus were significantly higher than that of A. membrane.（2）The contents of calycosin-7-glucoside,formononetin and polysaccharide in root of A. mongolicus were 1.8,1.6 and 1.3 times as much as that of A. membranaceus,respectively.（3）The root morphological distortion rate of A. membranaceus（70%）was significantly higher than that of A. mongolicus（53.1%）,and the confidence intervals of the root shape coefficient（RS1）of A.membranaceus and A. mongolicus were0.77 0.82and0.74 0.79,respectively.（4）The plant height,ground diameter and A/U values of A. membranaceus were 1.14-1.22,1.13-1.46,1.21-1.80 times as much as that of A.mongolicus（P＜0.05）,respectively,but the root length was significantly lower than that of A. mongolicus.Therefore,it is suggested that planting varieties should be selected species according to the production target.