Abstract: We analyzed the stomach contents of 146 bigeye tuna (Thunnus obesus) collected in the subtropical waters of the North Pacific (150°W−164°W, 30°N−37°N) from September to December in 2018 by the Chinese Longline Fisheries Observer Programme. A total of 36 bait species belonging to 28 families were identified. Alepisaurus ferox, Eucleoteuthis luminosa, Lestidium prolixum and Diaphus sp. were the dominant baits, whose relative importance index ratios (IRI%) were 25.65%, 14.48%, 7.56% and 6.77%, respectively. The feeding intensity of bigeye tuna reached the maximum value in the range of 100−110 cm fork length and at Stage III of gonadal maturity, while reached the minimum value at Stage V. Moreover, higher feeding intensity was observed at water layer of 150−250 m. The results improve the understanding of the biological characteristics and feeding habits of bigeye tuna, in addition to its important role in the ecosystem and food network structure.