Abstract: Urban rainfall-runoff model plays an important role in water resource management.Based on the storm water management model (SWMM),a drainage simulation system is established in Yalianfang catchment of Macau.The generalized likelihood uncertainty estimation (GLUE) approach is selected to analyze the parameters uncertainty of the complex rainfall-runoff model.Latin hypercube method is used to obtain sample sets,and Nash-Sutcliffe efficiency coefficient is used as the criteria of assessing the fitness between monitored time series and predicted one.The uniform pattern is determined as prior distribution of parameters.The results show that GLUE method is an efficient method to analyze parameters uncertainty of rainfall-runoff model,and the analysis results can offer information for further understanding to the modeling system.