Abstract: Seven Chinese local pig breeds, including Beijing Black pig, Yimeng Black pig, Laiwu pig, Bama Small pig, Diannan Small-ear pig, Wuzhishan pig, Xiang pig, and three foreign breeds, including Large White, Landrace and Duroc were used as experimental examples. A mutation in exon4 of pig Pit-1 gene in seven Chinese local breeds was found by using PCR-SSCP analysis. A RsaⅠ restriction enzyme polymorphic site in three foreign introduced breeds was detected by using PCR-RFLP analysis. The result of population genetics analyses showed that in the mutation of exon4, the frequency of A allele and AA genotype were significantly higher than B allele and BB genotype in the most of seven Chinese local breeds. A chi-square analysis suggested that Beijing Black pig and Bama Small pig reached Hardy-Weinberg equilibrium(P＞0.05), Beijing Black pig, Yimeng Black pig, Bama Small pig, Diannan Small-ear pig and Xiang pig had intermediate polymorphism(0.25<PIC<0.5). For RsaⅠ-RFLP, the frequency of A allele and AA genotype were higher than B allele and BB genotype. Large White and Duroc reached Hardy-Weinberg equilibrium(P＞0.05); and all of the three foreign introduced breeds had intermediate polymorphism(0.25<PIC<0.5).