Abstract: Abstract: Genetic diversity of Pinus massoniana Lamb. （mass pine） populations were evaluated using inter simple sequence repeat (ISSR) molecular technique. Amplification was conducted with 10 primers for 85 individuals selected from 2 populations. A total of 177 polymorphic were detected in Gupeng，The percentage of polymorphic marker (P) was 94.359%.The Shannon’s information index (I) and Nei’s gene diversity (h) were 0.4728 and 0.2765, respectively, A total of 168 polymorphic were detected in Shuilang.The percentage of polymorphic marker (P) was 94.38%.The Shannon’s information index (I) and Nei’s gene diversity (h) were 0.5190 and 0.3510,which indicated a high genetic diversity at species level. Gene differentiation coefficient among Gupeng groups was 0.0481 and 0.0363 among Shuilang,1gene flow of Gupeng groups was 9.8877, gene flow of Shuilang was 13.2643,which concluded that gene flow was not the factor for genetic differentiation among groups.