Abstract: The Middle Pleistocene Caryomys from Zhangping caves, Luonan County, Shaanxi Province is described into two extant species, C. eva and C. inez, that only live in North China. C. eva is characterized by 5 lingual and 4 buccal salient angles on m1 and by 3 lingual and 3 buccal salient angles on M3. C. inez is slightly more complicated than C. eva because its m1 has 6 lingual salient angles and its M3 has an elongated posterior loop with the fourth lingual salient angle sometimes. It is different from C. regulus living in Korea which has only 5 lingual salient angles on m1 and has the fourth lingual and buccal salient angles on M3. The average values of teeth are distinctly larger in C. inez than in C. eva (see Tables 1 and 2). The fact that the teeth have not evolved since middle Middle Pleistocene (493±55 ka BP) indicates that the genus Caryomys is a relatively conservative member of the subfamily Arvicolinae. Thomas (1911) proposed Caryomys as a subgenus of Microtus to contain the Chinese species inez, eva, nux andalcinous. Hinton (1923) at first elevated Caryomys to genus but later (1926) put it in Evotomys (=Clethrionomys) because he considered the holotypes of these species to be juvenile specimens of E. rufocanus shanseius. Allen (1940) concurred in recognizing inez (include nux) and eva (include alcinous) as two independent species but in the subgenus of Eothenomys. The specific validity of both is currently accepted (Nowak and Paradiso, 1983; Wang, 1991; Corbet and Hill, 1991; Wang and Xu, 1992; Huang et al., 1995). Ma and Jiang (1996) maintained to rehabilitate the Caryomys as genus based on the karyotypic study. Both eva and inez have 2n=54 with mostly subtelocentric pairs, while all Clethrionomys and Eothenomys sampled have 2n=56 with one metacentric pair. This result has been accepted by some biologists (Luo et al., 2000; Ye et al., 2002; Wang, 2003; Wilson and Reeder, 2005). The present authors also follow this view point.