Abstract: SSR was used to construct the heterotic grouping of 69 maize inbred lines,including 65silage maize inbred lines and 4domestic temperate common testers that represent 4heterotic groups used dominantly in China.Using 23SSR primers,67alleles were identified among the inbred lines.The average number of alleles per SSR locus was 2.9,ranging from 2to 5.Genetic similarity coefficient of dice was calculated using the software,NTSYS 2.10e,and a dendrogram of genetic relationship was constructed using UPGM A method.The cluster analysis classified these 65silage maize inbred lines into 4distinct clusters that would better reflect the relationship among them.