Abstract: Genetic diversity of 72 maize germplasm resources from 6 groups was studied by SSR marker. 57 primers detected 222 alleles amang the tested materials and per primer detected 2-8 alleles. Nei’s genetic distance varied from 0.0793 to 0.6637. The average genetic distances of the materials within the three special corn groups ( popcorn, sweet corn, waxy corn) were smaller than those amang them significantly. To three normal corns (flint corn, dent corn,semident corn), there were no significant differences of the average genetic distances within the groups or amang the groups. Variation range of genetic distance amang the special corn groups was smaller than amang the normal corn groups and between the two types also. Based on cluster analysis by UPGMA, 18 special corn inbred lines could be divided into 3 groups and coinsided with their group classification. Most of tested normal corns could be divided into 5 heterotic groups and mainly belonged to PB(31.5%), Lüda Red Cob(16.7%), and BSSS(14.8%).