We investigated the insect community along altitudinal gradient to gather basic data for distributional monitoring of insect species in the forest ecosystem. The investigation area was Seon-gaksan (Mt.) in Jinan-gun, Jeollabuk-do province, where the bucket-light trap and pit-fall trap for quantification were installed in Quercus vegetation at altitude of 300m, 600m and 900m. The field collecting was performed on May, July and September 2013 respectively. ANOVA analysis was conducted to analyze the significance between insect species along altitude using the collected insect community data. Analysis of variance (ANOVA) results showed statistically significant differences among ground-beetles and ants abundance with altitude as a response variable. Although we expected a distinct cluster with the difference of altitude at each study site, nonmetric multidimensional scaling (NMS) showed distinct clusters with the moth, ground-beetles, and ant assemblage at altitudinal increase and sampling month. In the result, a total of 309 species in 18 families of nocturnal moths were collected by bucket-light trap. The insects collected in pit-fall trap were ground-beetles with 196 individuals of 26 species and ants with 11,276 individuals of 14 species respectively.