Abstract: The major histocompatibility complex (MHC) DRB1 exon2 was amplified by polymerase chain reaction (PCR) from 122 healthy and 70 infectious with Dolang sheep. PCR products were characterized by the RFLP technique using three restriction enzymes, SacⅠ, Hin1Ⅰ and HaeⅢ. The results showed that rich polymorphism was observed in the exon2 of MHC-DRB1, which 2 ,2 and 6 RFLP patterns were found with enzymes SacⅠ,Hin1Ⅰ and HaeⅢ, respectively , and 3，3 and 18 kinds of genotypes were identified in Dolang sheep. By analyzing allele and genotype frequencies of healthy and infectious Dolang sheep, it was found that allele HaeⅢa was associated with susceptibility of hydatidosis (P＜0.05), and genotypes SacⅠab and Hin1Ⅰaa were resistant to hydatidosis (P＜0.05), while the genotypes of HaeⅢbe and HaeⅢ ef were rather highly susceptible to hydatidosis (P＜0.01).