Floating rice is an original rice population that has been growing in flooding condition in Long Xuyen Quadrangle for long time. However, the genetic diversity has been degrading and reducing in the area due to the changes of farming condition. The aim of this study was to evaluate the current floating rice population for future breeding and selection plans. The genetic diversity of 46 floating rice lines/varieties were evaluated by 20 SSR markers. The hierarchical method UPGMA (Unweighted Pair Group Method with Arithmetic Mean) was used for clustering analysis. The results of UPGMA showed that the genetic diversity was lower than 30%. The population was divided into four genetic groups with a difference of about 27% in genetic characteristics which were significantly different among the genetic groups. The studied results could be used for conservation or breeding purposes.