Abstract: Using FSHβ gene as the candidate gene, taking 518 sows （Duroc,Landrace,Yorkshire）as the research objects, the polymorphism of FSHβ gene sites was detected by electrophoresis of PCR products. Three genotypes were detected as AA ,A B,BB. The correlations between the genotypes of gene locus and total litter size, live litter size were analyzed. The results showed that the main genotype of FSHβ gene in Duroc ,Landrace and Yorkshire was BB genotype and the gene frequency of B in these three pig species were 96.67%, 73.36% and 86.01% respectively, but it had no significant effect on the litter size （P 〉0.05）. The first-born litter size of these three pig species with different genotypes had no significant difference （P〉0.05）. The effect of different genotypes on the total litter size had no significant difference （P 〉0.05）. In conclusion, the polymorphisms of FSHβ gene site had no significant correlation with the first- born litter size and total litter size of these three pig species.