To elucidate the genetic diversity and adaptive evolutionary mechanisms of different geographical populations of the plateau zokor （Eospalax baileyi）， in this study PCR was conducted to amplify and clone the MHC-DRB gene exon 2 in 121 individuals from eight distinct geographical populations. The results showed that the MHC-DRB exon 2 of the plateau zokor exhibits high polymorphism， with significant genetic differentiation among populations. Geographical isolation was identified as the primary factor driving population divergence. Codon usage bias was observed in nucleotide composition. Neutral tests indicated that the plateau zokor population had not undergone recent expansion， and the maintenance of genetic polymorphism was primarily driven by natural selection. The findings of this study will provide a theoretical basis for further investigating the genetic adaptation of MHC genes in Eospalax baileyi and their effective population management.

Eospalax baileyi  /  MHC-DRB exon 2  /  Polymorphism  /  Genetic diversity  /  Selective effect