Abstract: In order to investigate the nutritional quality of the muscle tissues of Decapterus macarellus from the South China Sea, the general nutritional composition, mineral elements, amino acid profile and fatty acid profile in both dorsal and ventral muscles were analyzed, and the nutritional value was evaluated. The results showed that no significant difference (P>0.05) was observed between the dorsal and ventral muscles in the content of moisture (69.35%~70.48%), protein (23.59%~24.60%) and ash (1.65%~1.79%). However, the fat content in the ventral muscles (0.94%) was significantly (P<0.05) higher than that in the dorsal muscles (0.74%). The contents of potassium (4599.9~4661.1 mg/kg) and magnesium (412.2~424.6 mg/kg) in the dorsal and ventral muscles did not differ significantly (P>0.05), while there were significant (P<0.05) differences in the contents of sodium (905.2~996.9 mg/kg), calcium (271.6~360.5 mg/kg), iron (11.1~13.1 mg/kg) and zinc (7.3~10.3 mg/kg). Specifically, the dorsal muscles exhibited higher zinc content, and the ventral muscles contained higher levels of sodium, calcium, and iron. The amino acid composition was similar between the dorsal and ventral muscles, with a high lysine content (2.1~2.2 g/100 g). The ratio of essential amino acids to total amino acids was 0.41, and the ratio of essential amino acids to non-essential amino acids was 0.69, meeting the criteria for high-quality protein. The essential amino acid index ranged from 0.75 to 0.86, indicating that Decapterus macarellus was an available protein source. There was no significant difference (P>0.05) in the DHA+EPA content (48.59%~50.00%) and the ratio of total n-6 polyunsaturated fatty acids to total n-3 polyunsaturated fatty acids. However, the ratio of total polyunsaturated fatty acids to total saturated fatty acids in the ventral muscles (1.51) was significantly higher than that in the dorsal muscles (1.44) (P<0.05). These results suggest that the muscle tissues of Decapterus macarellus, especially the ventral muscles, possess high nutritional value and represent a high-quality resource with potential for high-value processing and utilization in the South China Sea.