Single nucleotide polymorphisms (SNPs) of the porcine imprinting gene MKRN3 were identified in Meishan,Large white and Landrace pigs by PCR-RFLP and were genotyped in the F2 population of 285 Large white × Meishan pigs by PCR-BstUI-RFLP.Subsequently,correlation between the porcine gene MKRN3 polymorphism and porcine carcass traits were analyzed.The results showed that,the porcine MKRN3 gene had seven SNPs in the coding region,including 293C＞G,361G＞A,497G＞A,630G＞A,678T＞C,1376C＞T,and 1407T＞A.Of which,the 678T＞C site had different allele frequencies among domestic and foreigner pig species.In addition,the 678T＞C site of the porcine MKRN3 was associated with internal fat rate and buttock fat thickness significantly (P＜0.05).The 678T＞C site had a dominant effect on internal fat rate (P＜0.05),showing an increased internal fat rate with heterozygote form and had an additive effect on buttock fat thickness (P＜0.05),showing a decreased buttock fat thickness with the additive of the 678C allele.Therefore,the 678T＞C site of the porcine MKRN3 might provide a guiding value for the molecular breeding practice.