Abstract: On the basis of average Euclidean distance coefficient, using UPGMA, Q cluster analysis for karyotype of 11 populations in 5 taxa of Astragalus penduliflorus Lam. Complex have been conduc-ted. The results show that the karyotype of the eight populations of A. penduliflorus Lam, A. membranaceus var. membranaceus, A. minhensis and A. membranaceus var. purpurinus are vary in contin-uous pattern, while they are distinguished to the three population of A. membranaceus var. monghulicus in a interval pattern. As a result, we proposed that A. pendulifloms Lam should be treated as the synonym of A. membranaceus, and the complex might include two species(A. membranaceus(Fisch) Bunge and A. monghulicus Bunge), two subspecies (A. membranaceus spp. Membranaceus and A. membranaceus spp. Minhensis), and one variety (A. membranaceus var. purpurinus). The evolution of the karyotype of Astragalus pendulifloms Lam. Complex is consistent to Stebbins who regarded the evolution of the Karyotype in plants is from symmetry to dissymmetry.

Key words: A. penduliflorus Lam. Complex, Q cluster analysis, taxonomy