Abstract: An Hours-interval distributed hydrological model with a loosely coupled structure aimed mainly at simulating floods is proposed in this paper.The model is established on the basis of the DEM and composed of five components:the distributed digital basin,the unit grid module,the river rout ing module adjustment of water storage by reservoir model and the graphical user interface(GUI).With the support of GUI,the model can be run as model input,parameter selections and result display. The model can be applied to semi-arid and semi humid basin area with little ef ect from human activities,and is used in the upper Luohe River between Xiaolangdi and Huayuankou of the Yellow River basin.