Gaps are very important structure for the maintenance mechanism of tree populations, community organization or species diversity of forest communities. To evaluate gap structure and gap regeneration in well-preserved primary evergreen broad-leaved forests, this paper in the series of this study described actual states of canopy gaps and clarified gap regeneration of major tree species in oldgrowth evergreen broad-leaved forest stands, Tatera Forest Reserve, Tsushima, southwestern Japan. The results clarified the gap structure such as percentage gap area, gap density, gap size and characteristics of gapmakers etc. and the gap regeneration behaviors of major tree species in the stands
