[Objective] The research aimed to study the polymorphism of NCOA1 gene in pigs by PCR-RFLP.[Method] Using 81 Landrace pigs from Liuhe pig breeding farm as research objects,the genome DNA was extracted from ear tissue of pigs by conventional Phenol-chloroform extraction method.The genomic DNA was used as template to make PCR amplification and a 440 bp target fragment was obtained.PCR amplification products were digested by restriction nuclease Rsa I.The agarose gel electrophoresis detection was made.And the gene frequency and the genotype frequency were calculated.[Result] The agarose gel electrophoresis detection showed that the enzyme digestion products had three genotypes of AA (440 bp),AB (440 bp,282 bp,158 bp) and BB (282 bp,158 bp):The genotype frequencies of AA,AB and BB were 0.54,0.43 and 0.03,respectively:The frequencies of allele A and B were 0.76 and 0.24,respectively.[Conclusion] In the studied pig herd,A is the dominant allele and the genotype frequency of AA is higher.