This study was aimed to investigate the elevational and seasonal variation of moth diversity of Mt. Baegun-san, Gwangyang-city, Jeonnam. Moth collecting was carried out using a UV light trap at three different elevational sites from September to October 2014 and from April to October 2015 (9 times) except winter. A total of 288 moth species and 1,444 individuals in 15 families were identified. Geometridae (97 species and 740 individuals) were the most dominant in the numbers of species and individuals, followed by Noctuidae (62 species, 193 individuals), Erebidae (52 species, 177 individuals) and Notodontidae (16 species, 111 individuals). Elevational change showed that the lower elevation, the higher number of species and individuals. Seasonal change of numbers of species and individuals showed the M-shaped pattern with June and August peaks. Compared to the previous records from historical literatures, 197 species were newly added and the total moth species richness of Mt. Baegun-san comprised 449 species in 20 families. The Chao 2 estimated number of species using the observed species including unpublished data set was 1,530 species that comprised about 43% of the Korean Lepidopteran fauna. This large number of estimated species requested the more extensive and long-term survey for better understanding of the total moth fauna in this area.