In this paper, we updated the digital watershed data set of a coupled land surface and hydrologic model system (CLHMS) for the Pearl River Basin. The water cycle process of the Pearl River Basin during 1963-2006 was simulated using CLHMS. We evaluated the simulation ability of each water cycle component with the measured stream flow. The results show reasonable interannual responses of dominant water cycle components and good skills in simulating the monthly river flow of main stream. The wa - ter balance indexes (WBI) are close to 1, the Pearson correlation coefficient (PMC) are above 0.84,the IOA similarity coefficient are above 0.9, the skill of peak flow simulation still need to be improved.