Ten microsatellite markers were employed to analyze the genetic structure of four silver carp (Hypophthalmichthys molitrix) populations from Yangtze River,Ganjiang River and Poyang Lake and a total of 148 alleles were detected.The number of alleles per locus ranged from 5 to 24,the effective alleles ranged from 6.4 to 7.1,the average observed heterozygosity ranged from 0.802 to 0.821,and the average expected heterozygosity ranged from 0.817 to 0.839,indicating a high level of genetic diversity in the four silver carp populations.The genetic similarity coefficient ranged from 0.922 2 to 0.944 1,the genetic distance of these populations ranged from 0.057 6 to 0.081 0,the fixation index Fst values ranged from-0.012 35 to 0.005 28,which revealed that genetic consistency in the four silver carp populations was high,the genetic distance was small and the genetic differentiation was not significant.AMOVA analysis showed that genetic variation mainly came from within populations,and gene flow analysis indicated that genetic exchange of silver carp in Yangtze River,Ganjiang River and Poyang Lake was frequent.Our study provided valuable information on the germplasm resources of silver carp in Yangtze River,Ganjiang River and Poyang Lake,which could help develop appropriate policies on the conservation and utilization of silver carp.