This study is a statistical examination of the breeding avifauna on major islands in East Asia and the Australian regions. Based on the breeding distribution of all terrestrial birds, we calculated Simpson dissimilarity index between islands, using cluster analysis and Non-metric Multi-Dimension Scaling. Results show that the breeding avifauna on Lesser Sunda had strong Oriental affinities rather than Australian ones. The boundary between Oriental and Australian regions should fall between Lesser Sunda and Maluku. Moreover, the biogeographic boundary between Palearctic and Oriental regions should be located along the strait between Taiwan and Philippines. Ryukyu Islands and Kyushu may should be classified into different biogeographic sub-regions, as well as Hokkaido and Honshu. These biogeographic boundaries were related to the difference between the breeding avifauna on the islands, which may have been caused by land bridges and strait barriers resulting from sea level changes during the Pleistocene. While relevant studies have focused on faunal differences on continents, this study examined the biogeographic boundaries between islands and provides a unique viewpoint to the delineation of biogeographic regions.