The average heterozygosity value for each SSR locus ranged from 0 to 0.60, and the highest one was 0.96 (Fl0516 in 4013). The mean polymorphism index content (PIC) was 0.66 (range of 0.12–0.89). SSR markers are an efficient tool for fingerprinting cultivars and conducting genetic-diversity studies in the silkworm