National vegetation and habitat classification is well developed in most of the countries, but the classification systems are usually distinct and difficult to compare directly with each other. This incompatibility hinders cross-border, international studies of habitat characteristics which are necessary to effectively act on environmental issues, such as habitat conservation and biodiversity protection. To overcome this difficulty, the International Union for Conservation of Nature (IUCN) developed a global ecosystem typology (IUCN typology) based on the functional characteristics of ecosystems. The IUCN typology defines the topmost three hierarchical levels (Realms, Biomes, and Ecosystem Functional Groups) while individual countries can define further three levels from the bottom up. Japan has high-resolution vegetation maps provided by the Ministry of Environment (MOE), but they are available only in Japanese and not reflected in the coarse data associated with Japan by the IUCN typology. To foster accessibility for both international and Japanese researchers, we aligned the Japanese vegetation categories with the IUCN typology scheme up to Level 4, Regional subgroups, by matching the Japanese vegetation categories defined by MOE. Focusing on terrestrial ecosystems, we developed a correspondence table including English and Japanese terms and prepared a high-resolution spatial dataset coupled with land-use categories developed by the National Institute for Environmental Studies. By presenting the workflow of the integration together with a simple comparison of the newly developed high- and existing low-resolution IUCN categories, we hope to encourage both national and international researchers to take advantage of the system.