Abstract: Rapid urbanization has an adverse impact on urban rainfall-runoff processes and may increase the flood risk of urban regions. This study considered intensive human activities, such as increases in impervious area, changes in river network morphology, drainage system laying, and water transfer. We have developed two storm water management models (SWMM) based on remote sensing image and field survey, considering different urbanized scenarios and human disturbances and using measured streamflow data for model calibration and validation. Precipitation with different return periods was taken as model input to analyze the changes in flood characteristics caused by urbanization. The results indicate that these two models can produce good estimation of storms under the scenarios examined. The surface runoff after urbanization was 3.5 times larger than that before urbanization; the coefficient of runoff jumped from 0.12 to 0.41 and the amount of infiltration decreased from 88% to 59%. After urbanization, the time for overland flow concentration was shortened while the time for river concentration became longer; the flood peak time did not indicate much difference in this study. The peak flow of 20-year return period after urbanization is larger than that of 100-year return-period before urbanization. The results in this study would provide technical support to planning and management of urban storm water and evaluation on the low impact development technology.