In the present study,12 pairs of simple sequence repeat (SSR) primers were used to evaluate genetic diversity and genetic structure of Rhododendron molle G.Don in eight populations from six provinces.The results showed that:(1)A total of 260 alleles with an average 21.667 alleles per locus were amplified from 193 individuals.Average values of number of effective alleles (N_e) and polymorphism information content (PIC) were 5.425 and 0.900,respectively.This species has higher genetic diversity and gene flow among different populations.For R.molle,the Shannon’s information index (I) and Nei’s gene diversity (H) were 1.768 and 0.777,respectively.(2)Comprehensive analysis suggested that Jinxi (Jiangxi Province) population exhibits great level of variability,whereas the population of Zhenghe (Fujian Province) exhibits the lowest level of variability.(3)The genetic differentiation coefficient (F_st) based on infinite allele model (IAM) was 0.142 and the gene flow (N_m) was 1.522,respectively.Analysis of molecular variance (AMOVA) revealed that the genetic variation mainly occurred within populations (accounted for 87.71%),more than interpopulations (accounted for 12.29%).(4)The results of neighbor joining (NJ) analysis based on genetic distance and structure analysis showed that eight populations were clustered into three groups.The mantel test showed there was no significant correlation between genetic distance and geographical distance in R.molle.Our results indicated the priority should be given to in situ conservation,natural populations in Jinxi,Zhenghe,and Jingshan (Hubei Province) deserve prior conservation.The possible formation of the high level genetic diversity and the moderate differentiation of R.molle were also discussed.