Genomic DNA samples isolated from four geographical freshwater crab (Eriocheir sinensis) populations collected in the inland of the Korean Peninsula (Gunsan, Paju, and Nampo) and a Chinese site, were used for PCR amplification. Seven decamer primers generated 19 specific loci (19/243 loci, 7.81%) in the Gunsan population, 32 (32/215 loci, 14.88%) in the Paju population, 19 (19/231 loci, 8.23%) in the Nampo population and 62 (62/340 loci, 18.24%) in a Chinese population. The average 8.9 specific loci exhibited inter-individual-specific characteristics, thus revealing DNA polymorphisms in the Chinese population. The number of unique shared loci to each population and number of shared loci by the four populations were generated by molecular analysis using seven primers in four populations. 35 unique shared loci to each population, with an average of 5.0 per primer, were observed in the Gunsan population, and 50 loci, with an average of 7.1 per primer, were observed in the Chinese population. The hierarchical dendrogram indicates three main branches: cluster 1 (GUNSAN 01$sim$GUNSAN 05, PAJU 06$sim$PAJU 10 and NAMPO 11$sim$NAMPO 15) and cluster 2 (CHINESE 16, 17, 18, 19 and 20). Conclusively individual no. 20 of the PAJU 10 freshwater crab was most distantly related to CHINESE no. 20 (genetic distance = 0.667). Taken together, these results demonstrate the potential of RAPD analysis to identify diagnostic markers for the identification of four freshwater crab populations.