The mtDNA from three strains of triploid Carassius auratus: C. auratus gibelio (3N = 156 apprx 162), C. auratus pengze var. (3N = 162), C. auratus sogu var. (3N = 150) and C. auratus auratus (2N = 100) were studied by 16 restriction endonucleases. mtDNA RFLPs were produced inter-or intrastrains for 6 enzymes. Four haplotypes were found in C auratus gebilo, 2 in C. auratus pengze var., 3 in C. auratus auratus and 1 in C. auratus sogu var.. C. auratus gibelio and C. auratus pengze var. with the same common haplotype. The haplotype of C. auratus sogu var. is the common haplotype in C. auratus auratus. By data of restriction sites variant, the similarity and nucleotide diversity among haplotypes, nucleotide diversity of intrastrain and genetic distance among strains were calculated. It is determined that C. auratus pengze var. is a local population of C. auratus gibelio and C. auratus sogu var. is a variant strain of C. auratus auratus. The scientific name of C. auratus pengze var. should be C. auratus gibelo pengze var. Using the nucleotide divergence data between the two subspecies, the divergence time of C. auratus auratus and C. auratus gibelio is estimated to be at least 1.13 X 105 years.