Abstract: Genetic diversity and population structure of 303 sweetpotato landraces was analyzed by SSR markers．This study aims to understand the genetic relationship among sweetpotato landraces , and provide reference for the selection of excellent germplasm resource and the improvement of germplasm. Method:Using SSR to establish the 0, 1 database of the trial materials;The ntsys-pc 2.10 software was used to calculates the Nei72 genetic distance matrix;The genetic distance matrix was imported into MEGA 6.06 to output average genetic distance and cluster analysis. The results showed that 203 polymorphic sites were detected by 30 SSR primers, and 1 to 14 polymorphic bands which average 6.77 polymorphisms were detected for each primer. The average genetic distance of 303 accessions was 0.564. Cluster analysis in 0.087 genetic distance can divide 303 accessions into five groups, of which the fifth group in 0.115 genetic distance is divided into groups of A, B, and C. Population structure analysis of 303 accessions is divided into five groups. Clustering results coincide with the population structure.Q value of 70 accessions is less then 0.6 ,and these accessions were clustered into the mixed subgroup.