A phytosociological study of mantle communities was made in the Nansei Islands, southwestern Japan. As a result, 5 associations and 2 communities were classified. These vegetation units were contained in 2 alliances : Clerodendro-Derriion trifoliatae and Aristolochio-Clematidion ryukyuensis. The Clerodendro-Derriion trifoliatae is a tropical mantle community, and it occurs in the coastal areas of most of the Nansei Islands, especially in mangrove forest regions. The Clerodendro-Derriion trifoliatae includes 2 associations dominated by evergreen erect-type shrubs. Aristolochio-Clematidion ryukyuensis on the other hand is an endemic mantle community of the Nansei islands, and it occurs around many types of forest vegetation, e.g. natural Castanopsis cuspidata var. sieboldii forest and Leucaena leucocephala forest, in lowlands and mountain areas. The Aristolochio-Clematidion ryukyuensis includes 5 vegetation units, 1 association dominated by Rubus-type shrubs and 2 associations and 2 communities dominated by vines. Mantle communities in the Nansei Islands, as a whole, contain many evergreen vines, and are characterized by endemic species as well as tropical species. Their species combination differs from other northern areas of Japan.