Abstract: Pheobe zhennan is a unique and valuable timber tree plants in China. In order to reveal the genetic background and relationship among families, and to provide theoretical basis for the utilization of P. zhennan, 14 pairs of polymorphic SSR primers were used to analyze the genetic diversity of 39 P. zhennan families from 10 provenances in Sichuan Province. The results showed that a total of 178 alleles (Na) were detected by 14 pairs of SSR primers, and the average effective allele number (Ne) was 7.058. The PIC value varied from 0.306 to 0.939, with an average value of 0.746, showing high polymorphism of the SSR markers. Shannon's information index (I) ranged from 1.306 to 1.511, with an average value of 1.368, indicating that the P. zhennan provenances (families) had a relative high level of genetic diversity. The expected heterozygosity (He) and the observed heterozygosity (Ho) were 0.646 - 0.703 and 0.920 - 1.000 respectively, with an average of 0.676 and 0.550, respectively. The results of molecular analysis of variance (AMOVA) showed that 99% of genetic variation came from within provenances, and only 1% came from among provenances. Based on STRUCTURE software, the genetic structure was analyzed. When K=3, the ΔK had the maximum peak value, indicating that it was suitable to be divided into three groups. Based on the cluster analysis of genetic distance, 39 P. zhennan families were divided into four groups. Except for a single group of F20, the other three groups were mixed with other P. zhennan families from Chengdu, Luzhou, Ya'an and Leshan, and there was no obvious relationship between the classification of groups and the provenance sites. The study results provided a theoretical reference for the exploration of excellent gene resources and the selection of hybrid parents of P. zhennan.