In the Graduate School for International Development and Cooperation (IDEC), Hiroshima University, the development of Asian Environmental Simulator (AES) for the purpose of highly precise meso-scale environment simulation has been conducted. This simulator consists of the three major parts of the atmosphere-land surface interaction simulation, the atmosphere-ocean interaction simulation, and the estuary-coast simulation. The Research Project Center for Enviornment Simulator, in IDEC has been launched as a collaboration research program of Hiroshima University and Blue Wave Institute of Technology Co. Ltd., to improve the simulator's applicability at the business/practical level by applying it to the regional environmental problems. This article shows an outline of the environmental simulator and its examples of application to storm surge and high wave simulation, cohesive sediment transport in an estuary.