Abstract: Due to climate change and urbanization, coastal Chinese cities are facing increasingly severe flooding．A hydrodynamic coupling model was developed from InfoWorks ICM, model parameters were verified with measured rainfall and monitored water lever data at gully pot in the Baima basin in downtown Fuzhou on February 10, 2021．Four rainfall driving models with return periods of 10, 20, 50 and 100 a were used．Maximum inundation water depth was found to reach 0.402 m at 10:12 with rainfall return period of 10 a, 0.419 m at 10:07 with rainfall return period of 20 a, 0.438 m at 10:02 with rainfall return period of 50 a, and 0.450 m at 10:00 with rainfall return period of 100 a．To quantify flood risk, a 2D hydrodynamic model was developed based on topographic data．HR risk analysis was used to quantify and analyze flood risk．This study should be helpful for typical urban flood simulation and risk analysis in other regions as well．