Species composition and variation of catches in the coastal waters of Sinsan of Jeju Island were determined using samples collected by a set net from May 2014 to October 2015. During the survey period, a total of 55 species (51 species, 35 families and 11 orders in fishes, 4 species, 2 families and 2 orders in cephalopods) were occurred, and Perciformes (28 species) were dominant fishes in this area. In the number of individuals and biomass, the small pelagic fishes such as Trachurus japonicus and Scomber japonicus were occurred abundantly, and both species accounted for 95.9% of the total catch by a fishing logbook of a set net. In the results of length-frequency distribution of small pelagic fishes caught by a set net in Sinsan, T. japonicus showed a range from 3.5-19.1 cm (average 8.8 cm) and S. japonicus showed a range from 7.0-25.6 cm (average 16.8 cm). In addition, these were mostly immature fishes.