Genetic diversity of 74 pear rootstock germplasm resources was analyzed by using 9 pairs of specific SSR markers in this experiment. The results showed that 9 SSR markers amplified 57 alleles, with an average of 6.33 alleles per locus. 9 pairs of SSR primers could distinguish 70 pear rootstocks except for K11, K12, No. 13 and No. 15 of Pyrus betulaefolia Bunge. UPGMA cluster analysis showed that similarity coefficients were varied between 0.41~1.00, exhibiting high genetic diversity. All the cultivars were classified into 7 groups at the similarity coefficient of 0.67, which accorded with genealogical sources and geographic distribution.