Species composition and bimonthly changes of fish community were investigated with the fishes collected by using both trammel nets and fish pots in the coastal waters of Sagyeoi, Jeju Island from May 2009 to February 2010. A total of 1,921 individuals (324,206 g in biomass), which comprise 10 orders and 35 families with 60 species, were collected during the study period. Among 60 species, 52 species were caught by trammel nets, 20 species by fish pots, and 12 species by both fishing gears. The five dominant species were Pseudolabrus sieboldi, Plotosus lineatus, Pteragogus flagellifer, Sebastiscus marmorattus and Diodon holocanthus in the aspect of total number of individuals, and Diodon holocanthus, Sebastiscus marmorattus, Stephanolepis cirrhifer, Pseudolabrus sieboldi, Parupeneus chrysopleuron in biomass. Each characteristics of fish community such as the number of species, the total number of individuals, and biomass were highly correlated with water temperature and salinity, which were all statistically significant at the 5% significant level. In other words, there was a tendency of increment of each characteristics according to a raise in water temperature or a decrease of salinity, and vise versa. The number of species, the total number of individuals, and biomass of fishes were highest in August and lowest in February.