Ramdan H. 2015. Aplication of HESSA for mapping water providers and users in mountainous forest area. Pros Sem Nas Masy Biodiv Indon 1: 1719-1724. The montane forest ecosystem is water provider area that its water flows utilized by people to meet their consumption and production activities. Continuity, water quantity, and quality will remain intact if the condition of the forest ecosystem good. The responsibility of conservation of the forest ecosystem as area water providers also be the responsibility of water users through the mechanism of payments for ecosystem services (PES). The absence of water ecosystem services mapping method is a problem of PES implementation. This study aims to determine the spatial approach in mapping regions of water providers and users in the mountain forests. Methods of spatial analysis were done to water springs point in the field and are proceed by SRTM data (Shuttle Radar Topography Mission) using Global Mapper to be a map of water ecosystem services. The result showed that the HESSA (Hydro Services Spatial Ecosystem Assessment) method is effective to map the boundary between Water Provider Area and Water Users Area. The HESSA has been tested in protection and production forests in West Java Province. The HESSA spatial approach is a new innovation in the mapping of water ecosystem services. Map of water ecosystem services is very useful in PES implementation among water providers and users.