A study on the distribution and community structure of benthic macroinvertebrates on the intertidal zone of Cheju Island was carried out from June 1988 to May 1989. The macroinvertebrates collected and identified were composed of 7 phyla, 14 classes, 29 orders, 71 families and 135 species in this study. The dominant species of the upper tidal zone were Nodilittorina granularis and Heminerita japonica, those of the middle tidal zone were Monodonta neritoides and Lunella coronata coreensis, However, Monodonta neritoides and Chlorostoma arhyrostoma lischkei were dominant in the lower tidal zone. Community dominant indices were significantly high in the upper tidal zone. Macuoinvertebrates species which have the ability of resistance to the physical factors such as, strong waves and exposure to the hot sunlight were mainly distributed on the intertidal zone of Cheju Island. The difference in the number of species among seasons was not significant, but thao among zones was quite apparent and the lower the zone, the more abundant.