Abstract: ELA-DQA*exon2 locus was used to detect 300 horses of 7 breeds. The PCR amplified products of the loci were detected by 12 percent non-denatured polyacry lamide gel electrophoresis and showing in silver staining protocol. The results showed that 27 genotypes were detected in 300 horses: 10 homozygotes and 17 heterozygotes; The values of He and PIC represent highest polymorphism; Kimura 2parameter genentic distances between 10 alleles were from 0.015 to 0.147 and accorded Z-test（dN>dS）by sequense analysis. So horses had abundant polymorphism in ELA-DQA*exon2 locus.