The International Union for Conservation of Nature has recently developed a global ecosystem typology (IUCN typology) based on functional characteristics. However, the existing global maps for Level 3 of the typology (Ecosystem functional groups, EFGs) have low spatial resolution and fail to recognize certain categories in Japan limiting precise ecosystem analysis for global comparisons. To address these, we developed Level 6 classification, Subglobal ecosystem types (SETs), of the IUCN typology in Japan, directly under EFGs, by using the Japanese vegetation maps provided by the Ministry of Environment. First, we systematically identified potential parent EFGs for each Japanese vegetation categories, then conducted repeated iterative expert reviews until consensus was reached. Finally, we incorporated the land-use classification developed by the National Institute for Environmental Studies. The resulting correspondence tables and high-resolution spatial dataset include 133 SETs, belonging to 28 EFGs, 14 Biomes, and 7 Realms, focusing on terrestrial and related ecosystems. Within these Realms, the Intensive land-use Biome had the largest surface area, followed by Temperate-boreal forests and woodlands. Compared to the global maps, we identified seven new EFGs in Japan and extended the northern geographical range of some subtropical EFGs. SETs along climatic and anthropogenic gradients were challenging to align with existing EFGs, as were SETs related to characteristic vegetation communities in Japan and Asia, such as bamboo forests. The SETs created in this study enhance national assessments by providing spatially explicit information on ecosystem distribution and land-use, therefore can form an integral part of regional and global biodiversity monitoring.