Coupling radar-rainfall data with distributed hydrological model was important in improving flood forecast precision and leading time.However,radar-rainfall error propagation in hydrological model largely affected runoff process simulation.In this study,the operational radar-rainfall data,provided by Huaihe River basin Meteorological Center,was analyzed.With HEC-HMS hydrological model input,radar-rainfall data was used to simulate and analyze the runoff process of rainfall concentration period,in the Xixian hydrological station of Huaihe River basin,during July 1 10,2007.The results showed that runoff simulation based on radar-rainfall data was consistent with the simulation based on rain gauge data.The radar-rainfall input error had been decreased obviously after the propagation of the HEC-HMS model.Runoff simulation based on radar-rainfall data by union calibration was the best,whose relative error were-20.2% and-13.3% for flow process and peak flow,respectively.