Genetic diversity of 116 cucumber（Cucumis sativus L.）main cultivars from different regions was estimated using simple sequence repeat (SSR) markers. Three hundred and fifty five polymorphic bands were detected by 35 pairs of SSR primers. Each SSR loci can amplify2.46 alleles on the average. 70.99% of the total alleles were effective for genetic diversity analysis. The average Shannon's information index and PIC is 0.639 and 0.382, respectively. The genetic similarity (GS) varied from 0.5029 to 0.9797 among the 116 cultivars. These cultivars were divided into two groups at the genetic distance of 0.25 by cluster analysis. The first group consisted of 106 cultivars belonged to three ecotypes, north China type, south China type and Japanese type. And this group can be divided into five subfamilies. Ten cultivars belonged to European greenhouse type were in the second group.