We investigate the relationship between Rana coreana and Rana kunyuensis using morphological and molecular data. Morphological comparisons showed these two species to be identical in terms of body measurements and qualitative characteristics. Phylogenetic analyses found that R. kunyuensis and R. coreana are nested within a single clade and exhibited low divergence across several mitochondrial and nuclear genes. All evidence indicates that R. kunyuensis and R. coreana are the same species, making R. kunyuensis a junior synonym of R. coreana. This study stresses the importance of comprehensive taxon sampling, especially in neighboring countries.