In order to obtain information on the water regime of the Huaihe River Basin, the rainfall and runoff in the catchment upstream of the Wangjiaba sub-basin, in the main stream of the Huaihe River, were analyzed and simulated. Historical data from 1985 to 2007 in the basin were used for rainfall-runoff analysis. The distributed SWAT model was used for monthly rainfall-runoff simulation, and the SCE-UA algorithm was used for automatic calibration of parameters. The results show that 50% of annual rainfall was concentrated in the period from June to August. The mean monthly runoff and runoff coefficients of the Xixian and Huangchuan sub-basins in the southern mountainous area were higher than those of the Bantai sub-basin in the northern plain area. The determination coefficients of the simulation results of monthly runoff in the Xixian, Huangchuan, Bantai, and Wangjiaba sub-basins were 0. 77, 0. 81, 0. 69, and 0. 80, respectively. The rainfall in the upstream area of the Huaihe River areas shows a significantly seasonal centrality. The characteristics of runoff of the southern mountainous area and northern plain area are different due to terrain difference. The water conservancy facilities have significant influence on the change of rainfall-runoff processes, resulting in the simulated results of the Bantai sub-basin being inferior to those of other sub-basins. The study area is a runoff data-deficient area, and the distributed hydrological model adequately reflects the given information of the underlying surface, which can offset this deficiency.