Abstract: Many informative fragment of RAPD were obtained from Aphyocypris chinensis(Japan and China), Hemigrammocypris sp.(Japan), Gobiocypris rarus(China)by the method of random amplifing with 20 primers. We convert the DNA polymorphis fragment into genetic distance by the program Rapdplot(d=1-S, S=2NxNy/Nx+Ny). The matrix of genetic distance was caculated by the program Neighbor in software package Phylip, resulting in one cladogram of four species. This result indicated that the species Hemigrammocypris sp. is an independent one and the species Aphyocypris in China and Japan is the same species.