Abstract: 【Objective】To explore the relevance of myogenin(MyoG) gene polymorphism to body size, slaughter performance and meat traits of Yaoshan chickens. Breeding of Yaoshan chickens with regard to a molecular marker would better protect, develop and utilize Yaoshan chickens, and at the same time provide a reference for MyoG gene research in other chicken breeds.【Method】The experiment involved 150-day-old healthy Yaoshan chickens, using PCR product direct sequencing technology on the Yaoshan chicken MyoG gene. Polymorphisms were detected, and DNAStar was used to compare and analyze the sequencing results to determine the SNP site of the MyoG gene. SPSS 18.0 was used to analyze the correlations between SNP locus andgrowth, slaughter performance and meat quality, and RNAfold was used to predict the mRNA secondary structure before and after MyoG gene mutation in Yaoshan chickens.【Result】One SNP(T17C locus) was found in the third exon of the MyoG gene in Yaoshan chickens. It was a synonymous mutation, and there were three genotypes(CC, CT, TT);T was the dominant allele, and CT was the dominant genotype. The effective allele number(Ne) was close to 2.00, and the polymorphic information content(PIC) was 0.35, showing moderate polymorphism (0.25<PIC<0.50).In the Yaoshan chicken samples, except for the genotypic differences in breast width, leg muscle rate, chest muscle cooking loss rateand leg muscle cooking loss rate of the hen population, the differences in most other traits were not significant(P>0.05). The mutation at the T17C site of the MyoG gene changes its mRNA secondary structure, which in turn causes its minimum free energy to change from -452.60 kcal/mol to -465.24 kcal/mol. The results of correlation analysis among growth, slaughter and meat quality traits of different genotypes of Yaoshan chickens showed that most of the correlation analysis results among growth, slaughter and meat quality traits of the three genotypes showed the same trend. Among them, chest width and chest depth showed a very significant positive correlation in different genotypes of Yaoshan chickens(P<0.01).【Conclusion】There are three genotypes at the T17C locus of the MyoG gene in Yaoshan chickens, which are synonymous mutations and do not cause significant changes in the structure and function of amino acids and their proteins. However, the polymorphism has animpact on body size, slaughter traits and meat quality of Yaoshan chickens, so it can be used as a candidate genetic marker for molecular breeding of Yaoshan chickens.