The mathematical principle and numerical codes for geo-fluid dynamics in the meso-scale region, have been uniquely developed in the different fields. Nowadays it seems to be possible to combine these software resources to reproduce numerically a water circulation and material transportation in the land-river-coast system. With this situation, an environmental simulator in the humanosphere has been constructed by linking developed numerical models as an Atmosphere-Land Surface-Ocean Coupled Model. This paper proposes the development of Asian Environment Simulator (AES) in the Graduate School for International Development and Cooperation (IDEC), Hiroshima University, which is based on the developed Atmosphere-Land Surface-Ocean Coupled Model and the related database, such as DEM, land-use, soil, satellite data of TRMM, ALOS, IKONOS. Application of AES to environmental assessment and prediction in the developing Asian countries, may provide us scientific information for interdisciplinary studies on the development of social capacity for environmental management that is the 21st Century COE program at IDEC.