Skull character and dental pattern were described and 16 skull measurements were given in 14 specimens of Microtus kikuchii. The skull was rather large but less ridgy and angular. The number of re-entrant folds varied greatly at both sides in M3: three inner and outer folds are most frequent among the specimens examined. The number of closed dental spaces of M3 varied from four to six, and five ones were most common. The antero-external concavity of the anterior loop of M1 varied from indistinct to distinct type. A prominant first outer fold of M3 is observed in all specimens studied, and it suggests that the fold is a characteristic of the vole. The re-entrant fold of the second loop of M3 did not appear consistently Significant regression coefficients of seven skull measurements on zygomatic width (ZW) were shown except for interorbital width. By a regression line of condylobasal length (CBL) on ZW, the 95% confidence interval for CBL of the holotype specimen, whose basal part of braincase is damaged, was estimated as 30.97-31.99 mm, which is longest among the specimens examined and reported.