Enzyme electrophoresis was used to estimate genetic diversity and population structure of Corbicula papyracea in Korea. Seventeen of the 22 loci (77.3%) studied was polymorphic and mean genetic diversity at species level and at the population level were high (Hes=0.315; Hep=0.294, respectively). Populations of the Sumjin River appeared to have relatively high value of genetic diversity (Hep=0.328), whereas the value in the populations of the Nam River was distinctly lower (Hep=0.275). The genetic diversity trends to increase from the source of the main river to the mouth, showing a positive correlation between genetic diversity and geographic distance (r=0.84). Indirect estimate of the number of migrants per generation (Nm=2.14) indicates that gene flow is moderate among Korea populations of the species. In addition, analysis of fixation indices revealed a substantial heterozygosity deficiency in some populations and at some loci