In April 2010,thirty-six families were established by selecting mature breeders in the third generation selected line.In November 2011,four families were randomly sampled from the thirty-six families and subjected to the experiment where genetic diversity and kinship of the sampled families were analyzed using thirteen microsatellite markers.Thirty-nine alleles were detected at thirteen microsatellite loci in the four families and the number of the alleles at each locus ranged from two to five.The average observed and expected heterozygosity of the four families varied from 0.531 to 0.597 and from 0.474 to 0.507,respectively.The genetic differentiation index(F_ST)among the four families was 0.15.Based on the genotypes of offspring,all parental genotypes of the four families were successfully deduced. A dendrogram was constructed using UPGMA based on genetic similarity matrix.The UPGAM dendrogram of the 120 individuals indicated that 98.3% of the individuals from each family could be fully clustered and the classification results were consistent with the source of genealogy.Results show that there exists high genetic diversity among the four families and microsatellite marker is a useful tool for genealogical identification of pearl oyster.