Abstract: The nutritional quality and the proximate composition including the amino acid and fatty acid composition in muscle of wild P. leptocephalus in the Ussuri River were determined by routine methods. The results showed that the contents of moisture, crude protein, crude fat and ash in fresh muscle of P. leptocephalus were 77.98%, 19.05%, 1.66% and 1.20%, respectively. Eighteen kinds of amino acids were found in muscle of P. leptocephalus including 8 kinds of essential amino acids (EAA). In wet muscle, the content of total amino acids (TAA) was 19%, the content of EAA was 7.79%, 2 kinds of half essential amino acids (HEAA) were 1.63%, 8 kinds of nonessential amino acids (NEAA) were 9.57%; it was clear that the content of different amino acids was stable and the essential amino acid composition met the Food and Agriculture Organization of the United Nations/World Health Organization (FAO/WHO) standards. Four kinds of delicious amino acids (DAA) accounted for 6.99% in wet muscle. The contents of EPA and DHA in wet muscle were 4.20% and 8.04%, respectively. According to nutrition evaluation in amino acids score (AAS) and chemical score (CS), the limited amino acid of P. leptocephalus was Val and Try, and the essential amino acids index (EAAI) of P. leptocephalus was 90.05. The results indicated that the contents of amino acids and high-unsaturated fatty acids in muscle of P. leptocephalus were higher, and the composition of amino acids was reasonable, thus, P. leptocephalus is a high quality freshwater fish with high nutritive value and health value, which has good prospects for exploitation and utilization. 

Key words: Pseudaspius leptocephalus, nutritional composition, amino acids, fatty acids