Abstract: Fifty eight walnut cultivars（superior trees） were used as test materials to evaluate the population genetic diversity, analyze the genetic structure characteristics, and constructe the NJ cluster dendrogram of them by fluorescent SSR molecular marker technology, in order to accurately understand the genetic background and pro-margin relationship of 58 walnut germplasm resources, provide reference for rational utilization of Julans regiagermplasm resources, conservation of genetic resources and development of reasonable breeding schemes and strategies.The results showed that, 1)the 15 SSR primers screened out had high polymorphism, a total of 109 polymorphic alleles（Na） were amplified.The mean number of different alleles（Na） was 7.267,the mean number of effective alleles（Ne） was 3.069,observed heterozygosity（Ho） was 0.519,expected heterozygosity（He） was 0.653,polymorphism information content（PIC） was 0.603 5,and Shannon index（I） was 1.327.2)The genetic distance between 58 walnut cultivars ranged from 0.181 to 0.742,with a variation of 0.561.The proportion of genetic distance between 58 walnut cultivars ≥0.5 was 44.19%,and the proportion of genetic distance ≥0.6 was 13.5%.The 58 cultivars（superior trees） had broad genetic base, rich genetic information and high genetic diversity.3)Based on Nei genetic distance cluster analysis, 58 walnut cultivars（superior trees） could be clustered into 3 groups.The clustering results were related to phenotypic traits and genetic origin, but not related to geographical location.4)In population genetic structure analysis, Q＞0.6 accounted for 81.03%,and the proportion of gene mixed sources was high.