Abstract: The Randomly Amplified Polymorphic DNA(RAPD)technique was applied to assess the genetic variation among five populations of Tegillarca granosa. Under predetermined optimal reaction conditions, 154 RAPD sites were detected ranging from 300 bp to 2300 bp with 20 primers. The number of amplified bands ranged from 1 to 11 in every individual. The experimental data were analyzed with the Popgen 3.2 and PHILIP software. The results showed that: (1)no evident differentiation existed among the five populations, and they all belong to one community; (2) the nearest phylogenetic relationship occurs between the Korean population and Zhejiang populations, then between the Shandong and Fujian groups in turn; (3) the high level of mean heterozygosities suggests that the resource of Tegillarca granosa was in good condition with high genetic variation, and (4)the heterozygosities and proportion of polymorphic loci of the hatchery populations were lower than that of the wild population, which could be attributed to artificial or other factors. We suggest that it is important to take measures soon to maintain the germ plasm resource of Tegillarca granosa, so as to promote sustainable development of its aquaculture.