The SNPs of MC3R and MC4R genes in Jining Bairi chicken, Wenshang Luhua chicken and Laiwu Black chicken were detected by PCR-RFLP method. And the correlation between the polymorphism loci and the carcass traits were analyzed. As a result, an A/G mutation at nt 1 424 in MC3R gene and a G/T mutation at nt 923 in MC4R gene were identified，and the corresponding detection systems of DdeⅠand FbrⅠwere established. The statistical analysis showed that the MC3R polymorphism locus had a significant association with live weight (P=0.041 8) and breast muscle weight (P=0.012 6). The MC4R polymorphism locus had a significant association with intermuscular fat width (P=0.036 6)．The multiple–range test indicated that in MC3R polymorphism locus, the LSM of live body weight, carcass weight, semi-eviscerated weight, eviscerated weight and breast muscle weight of MN chickens were significantly higher than MM chickens or NN chickens (P < 0.05). In MC4R polymorphism locus, the percentage of LSM of carcass and intermuscular fat width of AB chickens were significantly higher than BB chickens (P < 0.05).