Currently, numerical models with a 20-100-km grid-spacing covering only a limited area of interest have been used to simulate regional climate. Such regional climate models (RCMs), however, are still insufficient for examining regional climate, since horizontal scales of severe phenomena accompanied by strong vertical motions are smaller than 20-100 km. Moreover, hydrostatic balance, which is generally assumed in most GCMs or RCMs, cannot be used in the simulations of severe phenomena with a horizontal grid of less than 10 km. The purpose of this study is to provide accurately downscaled regional climate over East Asia. The nonhydrostatic National Centers for Environmental Prediction (NCEP) Regional Spectral Model (RSM) is used as a tool. In addition to implementing a nonhydrostatic dynamical core, a nudging procedure for precipitation will be devised. A mixed layer model will be embedded within the RSM in order to improve air-sea interaction. A detailed description of the characteristics of the east-Asian summer monsoon will be presented through the high-resolution numerical simulations. The increase in horizontal resolution is expected to provide the high-quality data that can be used in various application areas such as air-pollution and regional ocean model forcing.