Moth diversity of Mt. Duryunsan and its neighboring area, Haenam, Jeonnam, collected from 2001 to 2004 is presented. A total of 498 species were identified and a logarithmic equation to the species accumulation data provided a good fit $(R^2=0.98;$ y=218.52 LN (x)+161.88), predicting that 665 moth species are expected after ten years of collecting. Yearly species accumulation data showed that the moth faunal composition was changing by the appearance and disappearance of species: $94~119$ species were newly collected in the following years; and $32~90$ species were not collected in the following years. The fourth year was the most species-rich with 250 species. The need of long- term research of speciose insect taxa is briefly discussed.