The composition of amino acids and the related compounds of nucleotides in the dorsal muscle of sweet fish Hemibarbus labeo, Mandarin fish Siniperca scherzeri and read fish Gobius similis was analyzed by amino acid autoanalyzer and high performance liquid chromatography. The result showed that IMP was dominant in the nucleotides of all the dorsal muscle of the fishes and a less amount of UMP, hypoxanthine and AMP was detected. In the free amino acid composition, the important amino acids were taurine and histidine in sweet fish, taurine, glycine and histidine in cornet fish, taurine, histidine and alanine in mandarin fish, taurine, proline and threonine in read fish, respectively, and in all the dorsal muscle of fishes, taurine was the dominant amino acid. In the amino acid compositions of the muscle protein, glutamic acid, glycine, aspartic acid and lysine were reached to 44.0% of total amino acids in sweet fish, glutamic acid, aspartic acid, lysine and glycine were 43.5% in cornet fish, glutamic acid, aspartic acid, lysine and leucine were 43.3%, 43.5% of total amino acids in mandarin fish and read fish, respectively. Glutamic acid was the dominant amino acid in all the fresh fishes.