Abstract: To study the polymorphism of myostatin (MSTN) gene and its association with growth traits in Chinese mitten crab Eriocheir sinensis, 321 individuals from the three populations (breeding population, contest population and wild population) were screened polymorphic sites of MSTN gene. Three SNPs were found in the first exon of MSTN gene, which were named as S1, S2 and S3, respectively (S1:C714T; S2:G729A; S3:G753T). These three SNPs were middle or high polymorphism loci, and they were all in hardy-Weinberg equilibrium (P>0.05) in population structure. A general linear model used to analyze the correlation between the three SNPs and growth traits (body weight and carapace length) of Chinese mitten crab indicated that S1 but not S2 and S3 had a significant effect on the growth traits (P≤0.05). The TT genotype was the most beneficial genotype on growth of Chinese mitten crab, which could be used as candidate for molecule marker-assisted breeding.