Three hundred and twenty seven Yorkshire, Landrace and Duroc pigs were analysed to screen the SNPs in 610 Exon of mitochondrial 2,4-dienoyl-CoA reductase 1(DECR1) gene and analyse its genetic structure. The resluts showed: the primers were designed accroding to human DECR1 gene by means of genome comparison, 2 SNPs were screened out in Exon6 and Exon8 by PCR-SSCP method, but mutation in Exon6 loic belonged to nonsense mutation, mutation in Exon8 loci belong to missense mutation. The polymorphism of the SNP in Exon8 were studied and 3 genotypes (CC, CG, GG) were tested in 3 breeds. There were abundant genetic polymorphism in Exon8 loci.