This is the first report on the introduced foreign species Mercenaria mercenaria in Korea after being changed to a newly given Korean name (scientific name). Imports of this cultured species from China are increased rapidly for food in Korean market. In this study, for the purpose of the managing genetic resources we used CO1 and 16s rRNA universal primer for genetic classification of this species and conducted the phylogenetic analysis on the nineteen species similarly related species with M. mercenaria. The similarities with M. stimpsoni which belongs to the same genus as M. mercenaria were 90.8% (16s) and 81.7% (COI). The similarity with Meretrix petechialis was 56.6% (16s) and 75% (COI), which was relatively very low. Therefore, it is assumed that the probability of genetic disturbances with similar species is low. In the near future, M. mercernaria is expected to be used as biological resources for the mudflats on the west coast in Korea.