The main purpose of this paper is to improve the warm rain process in the LASG-REM(State Key Laboratory of Numerical Model for Atmospheric Sciences and Geophysical-Regional ETA Model),via adding the explicit prediction of water vapor,cloud water and rainwater for mesh resolvable systems and the parameterization scheme for subgrid cumulus convective systems.The sounding data of Eurasian as well as the surface data at 0000Z 21st July 1998 are used as the initial fields in the simulation.Results show that the improved LASG-REM model is able not only to forecast rainfall of Wuhan area,but also to predict the temporal and spatial distribution of cloud water and rainwater successfully.