Abstract: This study evaluates the ability of the Abdus Salam International Center for Theoretical Physics (ICTP) version 3 Regional Climate Model (RegCM3) to simulate the summer rainfall amounts and distribution and largescale circulation over the Huaihe river basin(30°55′—36°36′N，111°55′—121°25′E) of China. We conducted the simulation for the period of 1982-2001 and one wet year of 2003 to test the RegCM3 ensemble simulation capacity. First, by comparing both rainfall amounts and distribution simulations against the observations, it turned out that RegCM3 can capture the rainfall patterns and annual variations. In addition, the simulated spatial pattern of the 850 hPa wind vectors and specific humidity field are close to the observation, while the RegCM3 output wind speed and specific humidity are larger than observation. Finally, the ensemble simulation of RegCM3 for the 2003 summer cannot capture the spatial center of the precipitation anomalies and underestimated the magnitude of the anomalies.