Abstract: Nutrients and composition of free amino acids in edible part of pearl oyster, Pinctada martenssi , were studied in this paper. The content of crude protein is 74. 9% ( dry basis) . The edible protein is rich in tasty amino acids such as 2. 21% glutamic acid, 1. 45% aspartic acid and 1. 01% glycine. The protein nutrient value is high because of the score of amino acid being 82 and the first limiting amino acid being sulfurcontaining amino acid ( Met and Cys) as compared with the FAO/WHO suggested level ( 1973) . Taurine is as high as 1. 38% , which account s for 74% of the total free amino acid. The edible part of pearl oyster is rich in minerals, especially microelement s Zn and Se.