Abstract:To explore the association of OOEP gene polymorphism with reproductive traits in Songliao Black Pig.130 sows were selected as the research object, and the SNP sites of three exons of OOEP gene were sequenced by Sanger direct sequencing method. The correlation analysis of OOEP gene SNP locus to reproductive traits of Songliao Black Pig was analyzed by SPSS 19.0 software. The results showed that SNPs were found in exon 2 of OOEP gene at 100 bp and 136 bp, named C100T and A136C, respectively. 3 genotypes were detected at C100T locus, CC, CT and TT. AA, AC and CC genotypes were detected at A136C. The results of population genetic parameter analysis and chi square fitness test showed that the two SNPs sites deviated from hardy Weinberg equilibrium(P<0.01), and the heterozygosity of C/T and A/C mutation sites was at the middle level, which was moderate polymorphism(0.25<PIC< 0.5), which could provide a little genetic information. The results of correlation analysis showed that the mutation sites of C/T and A/C in exon 2 of OOEP gene were found, The difference of the total number of piglets, the number of live piglets, the first birth weight, the weight of three weeks, the weaning weight, the number of weaning piglets and the number of nipples were not significant(P>0.05), TT(CC) genotype was higher than CC(AA) and CT(AC) genotype in total litter size, live litter size and weaning number. In conclusion, there are mutation sites C/T and A/C in exon 2 of OOEP gene, which is not significantly different from that of Songliao Black Pig. Whether it can be used as a genetic marker of reproductive traits needs further study in larger populations.