Based on the storm water management model (SWMM), an urban rainfall runoff model was established in Dahongmen drainage area of Beijing.The generalized likelihood uncertainty estimation (GLUE) method was chosen to analyze both the model un - certainty and parameter sensitivity. The results show that the proposed model is capable of simulating the urban rainfall runoff pro - cess. The manning roughness coefficient of conduit, the depression storage of impervious surfaces and the manning roughness coefficient of river, whose uncertainty are notable, have more influence on the model results than others. The analysis results can provide information for further development and parameter estimation of the urban rainfall runoff models.