PCR-RFLP were developed using the primers designed based on the sequence of PGR gene to determine the single-nucleotide polymorphisms (SNPs) of exon 1 of PGR gene in Landrace and Large White sows. And the influence of PGR gene on the total number born (TNB), number born alive (NBA) and litter birth weight (LBW) was also investigated. There were 3 genotypes (GG, AG and AA) in Large White sows, and two genotypes (GG and AG) in Landrace sows. There was a single base mutation (G→A) between GG genotype and AA genotype at position 326 bp, which caused a change of amino acid residue (Glycine→Serine). In Landrace sows, the differences of TNB, NBA and LBW between GG genotype and AG genotype did not approach statistical significance (P>0.05). In the Large White sows, the differences of TNB, NBA and LBW between AG genotype and GG genotype all reached statistical significance (P<0.05), while those differences between GG genotype and AA genotype did not reach statistical significance (P>0.05). The difference of TNB and NBA between AG genotype and AA genotype of Large White sows reached statistical significance (P<0.05), but the difference of LBW did not reach statistical significance (P>0.05).