A fragment(=350 base pair) of mtDNA at the cytochrome b gene site was amplified and sequenced to examine intraspecific variation of R. amurensis. The specific oligonucleotide primer set for polymerase chain reaction (PCR) was designed from a comparable published sequence of Xenopus leveis. Level of the partial cytochrome bgene sequence divergence was about 3% within species. The values were higher than those of another taxa, because certain regions of the sequence were identified as being particulaly differed. The results showed the those regions occur in 31-32 and 75, 78 (same numbering for the frog Xenopus laevis protein sequence). An interesting finding is that the regions showed variation within population. Therefore, these results suggest that the level of cytochrome b gene sequence divergence can be differed on the specific site. We have observed an example for the higher sequence divergence within species in partial cytochrome b gene.