The myostatin cDNA was cloned by means of RT-PCR and rapid amplification of cDNA ends (RACE),and its structural characteristics and phylogenetic relationship were also analyzed in the Mandarin Fish,Siniperca chuatsi. The full length of mandarin fish MSTN cDNA was 2 627 bp,and it contained a 117 bp 5′-untranslated region,a 1 376 bp 3′-untranslated region and a 1 134 bp open reading frame( ORF),which encoded 377 amino acids with a putative signal peptide of 22 amino acids. A conservative hydrolytic site, RARR and 9 cysteine residues,the common domains of vertebrate MSTNs,were identified in mandarin fish MSTN. Mandarin fish was grouped into the same branch as other fishes in vertebrate MSTN phylogeny. RT-PCR analysis demonstrated that the mandarin fish MSTN transcript expression varied among different tissues. Its expression was detected in ovary,kidney,eye,muscle,heart,brain,skin and stomach,but not in liver.