An investigation of fauna and community of insects in Gotjawal Terrain, Jeju-do, had been conducted with a way of black light trap from July to September, 2005. The investigated insects were classified into 217 species, 75 families, and 11 orders respectively. Coleoptera that occupied 55.3 percent among them and was consisted of 120 species was the richest group and Hemiptera followed it. The density of Physopelta gutta was highest but Physopelta cincticollis was overall the dominant species in all sampling areas. The species diversity index was highest at Jocheon-Hamdeog Gotjawal in Jeju-do, while it was lowest in Gujwa-Sungsan Gotjawal. Clustering analysis revealed that the insect communities of four localities were grouped in only one cluster. Included in the species unreported in Jeju Island were Menida musiva and Pentatoma japonica in Hemiptera, Philonthus wuesthoffi in Coleoptera, and Phanerotoma flava in Hymenoptera.