Zoco's position has been in chaos. Monopterinae has been classified as Rodent (Alston,1876; Thomas,1896; Ellerman, 1940,1941; Musser et al., 1993), Leucaenae (Tullberg,1899; Miller et al., 19 18) and Carnivora (Simpson,1945; Chaline et al.,1977; Xun et al., 2000). According to the characteristics of skull, Lawrence (199 1) thinks that zokor is a group independently developed from rodent species and evolved from other types of rodent family. Recent molecular studies have also pointed out that zokor should be classified as Carnivora (Michaux et al., 200 1), or be classified as Zokor with its closest relatives, bamboo rats and blind rats (Jansa et al., 2004; Norris et al., 2004). Most foreign scholars tend to classify zokor into zokor family, while most Chinese scholars still classify it into zokor family and follow the traditional classification.

Zokor subfamily *** 1 Genus 2 subgenus.

Namely: zokor and Eospalax. Subgenus Zokor is distributed in China, Mongolia and southern Siberia of the former Soviet Union. Subgenus Zokor is only distributed in China. Taxonomists mainly rely on G. Allen (1940), οгнев (1947) and ellerman (195 1). However, there is no consensus on the classification of species and subspecies within the genus.

G Allen (1940) divided zokor into two types, namely, M. aspalax and M. m. psiluruls；; сигнев (1947) can be divided into three species, namely: the sky mouse, the naked mouse and the zokor mouse; ; B.A. кунецов (1965) and G.B. Colbert (1978) agree with A.A.. According to Li Hua (1995), there should be two species of zokor in this subgenus, namely, the northeast zokor and the grassland zokor, and their notable feature is that 1 or 1 has two deep concave angles on the inner side of the upper molar, and there is no transitional type. The two concave angles on the inner side of the upper molars of Chinese zokor larvae 1 are deep, but gradually become shallower with the growth of individuals, forming two concave angles with different depths. In order to avoid confusion, the northeast zokor and the grassland zokor can be distinguished from the third upper molar and the incisor hole.