Fishes were caught by a set net in the coastal waters off Yosu, Korea from April to October, 2001, and seasonal variation of abundance and species a composition were studied. Fifty two species were identified as fish (89%), cephalopods (10%) and crustaeans (1%). Of the fishes Engraulis japonicus, Trachurus japonicus and Trichiurus lepturus were dominant species representing 64.1% in total number of individuals. The number of species was high in spring and low in summer; number of individuals was high in spring and low in autumn. The diversity index (H) was 0.4-0.7. The abundance and species composition fluctuated seasonally. Occurrence of the various stages of fishes indicated that Scombia japonicus, T. japonicus and E. japonicus utilized in the area as spawning ground, Conger myriaster larvae, Ammodytes personatus and Seriola quinqueradiata as nursery ground, and T. lepturus and Ilisha elongata as spawning and nursery grounds.