This study was to investigate the feeding habits of the Notchedfin threadfin bream (N(emipterus peronii() by analyzing the stomach contents of 1029 specimens, which were caught from southwestern Taiwan by trawlers from January to December, 1998. The diet composition indicated that N. peronii was a polyphagous fish. Crustaceans and teleost were the dominant preys of N. peronii, which occupied 52.8% (including 3 families and 4 species) and 43.1% (including 9 families and 13 species) of the total food items, respectively. The top 4 food items were shrimp (22.6%), Harpadon microchir (19.9%), Crab (18.4%) and Sergia lucens (10.0%). Seasonal variation in diet composition was significant. In spring and winter seasons, the highest of occurrence frequency was crustacean with 90.7% and 76.1%; and the secondary was mollusca with 51.8% in spring and fish with 25.0% in winter. However, the highest frequency in summer and autumn was fish with 56.7% and 73.7%, then crustacean with 49.5% and 59.3%. In addition, the highest weight percentage in spring and summer was crustacean (65.5% and 78.1%), and secondary was fish (26.5% and 15.3%). On contrary, the highest in autumn and winter was fish (60.5% and 52.1%), then crustacean (38.9% and 40.8%). However, there was no significant different between female and male’s feeding habits whether having different sizes.