To determine the nutritional composition of Decapterus maruadsi muscles and systematically analyze the nutritional value of Decapterus maruadsi muscles so as to give it a reasonable evaluation, the national standard biochemical assay method was applied to detect the moisture, crude protein, crude fat, crude ash, amino acids, fatty acids and minerals of the Decapterus maruadsi muscles. The results showed: The moisture content in muscles of Decapterus maruadsi was 75.00%, the dry weight content of crude protein, crude fat and crude ash were 79.52%, 9.88% and 4.16% respectively. 18 kinds of amino acids were detected with the total content of 75.24% (dry weight), in which the essential amino acids accounted for 30.08% of total amino acids. The content of was glutamic acid the top(11.40%). The main limiting amino acids were tryptophan and valine, and essential amino acid index (EAAI) was 83.32. 17 kinds of fatty acids were found in muscles with the top content of palmitic acid (2.60%), and the total content of EPA and DHA was 2.20%. The mineral elements were rich in muscles, such as P, K, Ca, Na, Mg, etc. The top major element of P was 2193.99 mg/kg and the top trace element of Fe was 22.25 mg/kg. It is concluded that Decapterus maruadsi is a kind of the high quality economic fish that have high protein and low fat, high nutritional value and high economic value. It has great potential for comprehensive exploitation and utilization.