Hydraulic model of Huaihe River with flood diversion and flood retarding areas was developed for flood forecast.The in-put flood discharge hydrograph from the main channel to the flood diversion area is estimated with the fixed split ratio of the main channel discharge.The Muskingum discharge routing method is applied in the flood diversion area,and outflow can generate only after it reaches full storage.The flood flow inside the flood retarding area is calculated as a reservoir and inflow and outflow are cal-culated based on the water balance equation.Taking complex river basin between Wangjiaba and Lutaizi stations with flood diver-sion and flood retarding areas of Huaihe River as an example,with taking the Linhuaigang Project as inside boundary in flood rou-ting,Hydraulic model of Huaihe River based on one-dimension hydraulic model was developed.In order to testify the performance and rationality of the developed model,the representative flood events from 2003 to 2008 were forecasted with the developed hy-draulic model.Results show that the developed model performs well and is reasonable.