The main agronomic traits of 143 accession of rice germplasm including the weedy rices,improved cultivars and rice landraces,which were from Ningxia province,were evaluated in Ningxia,and the genetic diversity,genetic similarity and cluster analysis of different rice germplasm were conducted using a total of 24 SSR markers distributed on 12 chromosomes.The results of phenotypic analysis showed that,Ningxia weedy rice was dwarf and early maturity,phenotypic variation range was large;pericarp was mostly red colored,glume color was straw yellow,all plants were prone to seed shattering.The results of SSR analysis showed that totally 141 alleles were detected,and the number of alleles per pair of primers ranged from 3 to 11 with a mean value of 5.8333.Nei's genetic diversity index (He) ranged from 0.2241 to 0.8065 with the average of 0.5219.The number of alleles (Na),the effective number of alleles (Ne) and the Shannon polymorphism index (I) in weedy rice were higher than that in improved cultivars and landraces.In the different sources of weedy rice,Nei's gene diversity index (He) of weedy rice from Wuzhong and Yongningdonghe were the highest with the value of 0.4912 and 0.4814,while that of weedy rice from Qingtongxia was minimum with the value of 0.2802.Similarity analysis showed that weedy rice is high similar with local varieties,the similarity coefficient was as high as 0.9585,while the similarity of improved varieties and weedy rice was the lower,the similarity coefficient was 0.4584;the similarity coefficient of landrace and improved cultivars was only 0.3560.The cluster analysis showed that the tested materials were cluster into three categories.Improved cultivars were fallen into category Ⅰ,its genetic background was significantly different from that of weedy rice and landraces;and most weedy rice and landraces were fallen into category Ⅱ, different sources of weedy rice and landraces were more evenly distributed,category Ⅲ was composed of a small part of weedy rice and landraces.Distribution of weedy rice in Ningxia was no obviously regional,and weedy rice and landraces are integrated highly and high genetic similarity.