Collection of moths in four Gotjawal terrains of Jeju Island was conducted using black light trap, beginning July through September 2005. The insects investigated were classified into 146 species, 15 families and 7 superfamilies, and Noctuoidea appeared to have accounted for 41.1%, or 60 species, which was the largest number among them, followed by Geometroidea. Ercheia niveostrigata was found to have been the dominant species over the entire area. The diversity index showed the highest at Aewol Gotjawal and the lowest at Hangyeong-Andeog Gotjawal. Aewol Gotjawal formed a cluster with Gujwa- Sungsan Gotjawal at the lowest chord distance (0.75). At the higher chord distance of 0.82, Jocheon- Hamdeog Gotjawal fused the cluster of Aewol Gotjawal and Gujwa-Sungsan Gotjawal. Hangyeong-Andeog Gotjawal fused with the rest three terrains, forming a single cluster at the highest chord distance of 0.89.