This study demonstrated integrative assessment of mangrove resource use in Iriomote island in order to seek sustainable use of the resources. First, we found that the ways of mangrove use had shifted from direct ones (use for raw materials such as tannin and dye) to indirect ones (like for ecotourism). Second, the mangrove forests in Iriomote island substantially lost its coverage in the last decades. Third, with the second results, we confirmed that the direct use of mangrove resources was not sustainable even after considering other influences such as natural disaster. Fourth, we showed economic merits and cultural aspects as well as the environmental reasons mentioned above are the major reasons that ecotourism as an indirect use of mangrove use was employed and established. Finally, based on the results of the integrative assessment, we argue that further efforts are necessary to conserve the mangrove resources and their landscape under the current practice of ecotourism.