Abstract: BoLA-DRB3 is a member of the MHC (Major Histocompatibility Complex), which plays a central role in immune system and disease resistance of bovine. The exon2 of BoLA-DRB3 gene is a mainly functional region, which codes the antigen and participates in the body’s immune response. In this study, the 307 bp fragment including the exon2 in Luxi , Qinchuan, Nanyang and Jinnan cattle was amplified by polymerase chain reaction, which was digested with restriction endonuclease MspⅠ. The results showed new allele was produced by the mutation of C to A at position 154 in exon2. Statistical results of χ² test indicated that genetic polymorphism sites of the exon2 of BoLA-DRB3 locus in Luxi cattle did not fit Hardy-Weinberg equilibrium (P<0.05).