Abstract:In this paper, genetic diversity of five wild silver carp(Hypophthalmichthys molitrix)populations, collected from the Yangtze River, Pearl River and Heilongjiang River was analyzed using 34 microsatellite markers. The observed(Ho) and expected heterozygosity (He),polymorphism information content(PIC) and number of effective alleles(Ae) were all determined.The genetic similarity coefficient and Nei'S standard genetic distance were computed based on the allele frequencies.The HardyWeinberg equilibrium was checked by X2 test.Genetic differentiation and hierarchical partition of genetic diversity were evaluated by FSTand Nm.A dendrogram was constructed based on NJ method using MEGA3 software package .For each locus, 1-9 alleles were amplified with an average of 4.666 7,adding up to 154 alleles in all five populations, of which the mean valid alleles were 2.948 9.We found the genetic variability level was moderate in the five populations, as shown by Ho(0.329 5-0.461 9),He (0.500 2-0.552 9) and PIC(0.443 5-0.493 0),respectively. Based on the genetic similarity coefficients and genetic distance, the genetic diversity between the two groups of Yangtze and Pearl Rivers(Ds=0.1852) was higher than that of the two populations of Heilongjiang and Pearl Rivers(Ds=0.1558). There were no obvious relations between genetic distance and geographical distribution of the five populations.