In order to understand the genetic relationships among numerous materials of common wild rice in Hainan province and explore representative samples， this study used 32 pairs of SSR markers to conduct genetic diversity analysis and core germplasm construction on 2038 samples of Hainan common wild rice from 11 different cities and counties in Hainan province. The results showed that the average effective allele （Ne） was 2.479， the richness Shannon index （I） was 0.975， the Nei′s gene diversity （h） was 0.570， and the percentage of polymorphic loci was 96.27%， indicating that the genetic diversity of Hainan ordinary wild rice is very rich.There are differences in genetic diversity among Hainan common wild rice from different sources. Common wild rice from Lingao has the highest genetic diversity， while Qionghai common wild rice has the lowest genetic diversity， and its variation is mainly concentrated within the population. The analysis of population structure showed that when K=2， the Delta K value was the highest. 2038 ordinary wild rice resources from Hainan were divided into two groups. The subgroup Ⅰ has 1145 resources， which come from Haikou， Chengmai， Danzhou， Sanya， Wanning， Qionghai， Lingao， Lingshui， Ledong， and Dongfang， respectively. The subgroup Ⅱ has 893 resources， which come from Haikou， Wenchang and Chengmai， respectively.192 core germplasm of Hainan common wild rice were constructed using population first and multiple clustering methods， accounting for 9.42% of the total resources （2038）. The Shannon index （I） of the core germplasm was retained by 102.46%， and the Nei′s gene diversity （h） was retained by 104.39%， effectively reducing the genetic redundancy and duplication of genetic differences in the original germplasm. The core germplasm of Hainan common wild rice represents the genetic diversity and specificity of the original germplasm， and provides materials for the effective utilization of Hainan common wild rice resources.