We investigated karyotypes, mitochondrial cytochromeb gene sequences, and cranial morphometries of the water shrewsChimarrogale himalayica (Gray, 1842) andC. platycephala (Temminck, 1842) (Insectivora, Soricidae). Karyotypes ofC. himalayica from Taiwan andC. platycephala are 2n=52 and FNa=100. Autosomes consisted of 21 large-to-small metacentric or submetacentric pairs, and 4 medium-to-small subtelocentric pairs. The X and Y chromosomes were medium submetacentric and small acrocentric, respectively. The karyotypes ofC. himalayica andC. platycephala were very similar. Secondary constrictions were observed in the largest metacentric pair in both species. In the 930 base-pairs of the cytochromeb gene,C. himalayica from Taiwan andC. platycephala diverged with 9.46% sequence difference; each species diverged fromC. phaeura with more than 14% sequence difference. The two speciesC. himalayica andC. platycephala were well distinguished by morphometric characters, but three subspecies ofC. himalayica were not clearly separated. We suggest thatC. platycephala be treated as a valid species and separated fromC. himalayica in Taiwan.