Abstract: Funded by the project of flood risk map in key areas of China,China Institute of Water Resources and Hydropower Research (IWHR) developed two flood analysis software, which are IFMS, Integrated (IWHR) Flood Modeling System(1D+ 2D) and IFMS Urban, Integrated(IWHR) Urban Flood Modeling System(2D+SWMM). A high resolution two-dimensional flood model was developed and the storm water management model (SWMM) was integrated in IFMS Urban. Based on self-developed GIS platform, coupling of urban drainage network with two -dimensional model can be realized. This paper presents an introduction to IFMS Urban and illustrates several typical applications in the urban flood risk mapping. The successful application of IFMS Urban in cities such as Chengdu, Hohhot and Taiyuan shows that it has the ability to deal with complicated actual urban flood problems.