Abstract: 52 Prunus salicina germplasm from 5 regions in Guizhou Province were used as the test population. 10 ISSR core primers selected for the 52 Prunus salicina samples were conducted by relatedness analysis and genetic evaluation. The results showed that the 10 core primers amplified a total of 76 loci in the 52 Prunus salicina samples, with an average of 7.6 loci per primer, of which 73 loci were polymorphic, with an average polymorphism rate of 96.05%. UBC842 and UBC856 amplified the most loci, with 10 loci, while UBC834 amplified the least loci, with only 6 loci. The number of alleles（Na） ranged from 1.625 0 to 2.000 0 with a mean value of 1.888 9, the effective number of alleles（Ne） ranged from 1.324 4 to 1.696 5 with a mean value of 1.509 3, the Nei’s gene diversity index（H） ranged from 0.221 4 to 0.391 6 with a mean value of 0.300 4, and the Shannon’s information index（I） ranged from 0.336 5 to 0.571 4 with a mean value of 0.452 3. The overall results indicated that the genetic diversity of the test samples was relatively high and the selected ISSR primers could be used to study the genetic diversity of Prunus salicina, and could provide reference and technical support for the breeding of new germplasm and conservation of resources.