Abstract:A total of 82 SSR markers Distributed in 12 chromosomes were used to analyze genetic diversity and genetic similarity in 59 rice varieties of Ningxia after 1980s. 339 alleles were revealed, and 2 to 19 alleles were identified among different loci. The mean number of alleles per locus was 4.13. Total genetic diversity index of Nei varied greatly among loci from 0.0333 to 0.8164, with an average of 0.4394. The 55 rice varieties were divided into 3 groups according to their released years. With the increase of the year, both the number of alleles and genetic diversity showed an increasing trend significantly (P <0.001). UPGMA cluster analysis showed that the 59 rice varieties were cluster into five categories at the level with genetic similarity coefficient of 0.75. The category Ⅰ has only one aromatic rice, Ⅱ and Ⅳ both have three varieties, and category Ⅲ contains five varieties similar to Jilin rice. The most rice varieties were clustered into category Ⅴ, which accout for 79.7% of the tested varieties. Compared the pedigree of rice varieties, the vast major varieties have kinship of Ningxia core parental such as Hongqi 12, Jingyin 39, Dongfanghong 2, Jingyin 59, etc, which showed close relationship among varieties. Although the genetic diversity of Ningxia rice has increased in recent years, the genetic basis is still narrow. The similarity coefficient of the tested varieties is above 0.75, even as high as 0.94. Breeders must introduce and innovate in more rice parental materials in order to expand the genetic foundation of Ningxia rice in the future.