Feeding habits of white croacker, Pennahia argentata, were analyzed by using the stomach contents of 153 specimens caught by bottom trawl from May 2011 to March 2012 in the Sejon island, Korea. To know feeding habits of the white croacker, P. argentata, a species composition and it’s fluctuation were analyzed based on growth. White croacker, P. argentata caught in the area composes 15 species. The most species in an number of the prey was Macrura which was occupied at 66.4% from whole prey, the second most species was Pisces which was occupied at 20.3%. The most species in an wet-weight of the prey was Pisces which was 49.3% out of the whole specimens. The second most species was Macrura which was 43.3%. The frequency occurrence of the prey was Macrura which was 68.6%, the next one was Pisces which was 28.8%. The highest Index of Relative Importance (IRI) of the prey was Macrura which was 78.2%, the next one was Pisces which was 28.8%. A number of the prey per specimen of small, middle and large class were 1.3, 1.5, 1.7, respectively. A wet weight of the prey per specimen of small, middle and large class were 0.2, 0.6, 0.2 g, respectively.

The study aims at analyzing a species composition of the fish live in bottom of the coastal waters off Geomun island, Korea. To reach the goal of the study, a species composition and it’s monthly fluctuation, a monthly fluctuation of the dominant species and it’s appearance type was analyzed the fishes caught by the bottom trawl. The result obtained can be summerrized as follows; Fish caught in this area composes 14 orders, 34 families, and 47 species. The largest number of fish species was Perciformes (15 families and 19 species). The most dominant species in an number of fish was jhon dory, Zeus faber which was occupied at 22.5% from the whole number, the second most dominant species was horse mackerel, Trachurus japonicus which was occupied at 21.2%. Four groups were categorized based on appearance time period.