Abstract: By exploring the nutritional changes of Lateolabrax maculatus and Micropterus salmoides with different quality specifications, the accumulation pattern and nutritional quality of nutrients during their growth process were analyzed. The results showed that 16 amino acids were detected in both Lateolabrax maculatus and Micropterus salmoides muscles, including 7 essential amino acids （EAA）, 2 semi-essential amino acids （SEAA）, and 7 non-essential amino acids （NEAA）. The protein content in the muscles of Lateolabrax maculatus and Micropterus salmoides ranged from 18.20% to 21.80%, fat content from 1.24% to 4.25%, moisture content from 72.10% to 78.30%, ash content from 1.14% to 1.31%, total amino acid content from 17.37% to 20.72%, and essential amino acid content from 7.01% to 8.21%. The variety of nutrients in sea bass was complete and balanced. Lateolabrax maculatus and Micropterus salmoides had certain differences in nutritional composition, and the nutritional components of sea bass of different quality specifications were not the same. The content of various amino acids in the large-scale Lateolabrax maculatus was the highest, and there was a significant difference （P<0.05） compared to other Lateolabrax maculatus samples; the various amino acid contents of the large Micropterus salmoides were the highest, and most of the amino acid contents were significantly different from those of other Micropterus salmoides samples （P<0.05）, indicating that the large sea bass accumulated more amino acids during the growth process. From the perspective of amino acid balance, medium-sized sea bass was the most suitable for consumption.

Key words: Lateolabrax maculatus, Micropterus salmoides, muscles, nutritional quality