Abstract: Nutritional components of Akami, Chu- toro and O- toro muscle from bigeye tuna were investigated.The results showed that the crude protein, essential amino acids content and essential amino acids index (EAAI) of Akami were 24.84%, 34.08% and 88.08, higher than 20.67%, 24.90% and 84.80 of Chu- toro, 19.56%, 25.09% and 85.93 of O- toro, respectively.This indicated that the nutritional value of amino acids from Akami was the best, Chu-toro take the second place and O- toro was the last.The content of poly- unsaturated fatty acids such as DHA, EPA from Akami was 41.00%, higher than 28.12% of Chu- toro and 23.72% of O- toro, but its crude fat content was only 0.16%, which significantly lower than 4.80% of Chu- toro and 6.35% of O- toro, lead to the nutritional value of fatty acids of Akami far lower than Chu- toro and O- toro.The contents of minerals were also abundant in three muscle parts.