In recent years， many hydrologic stations have been built in Jiangxi province.Because of the lack of measured data，it is difficult to construct the flood forecast scheme of these stations.In this paper，a flood forecasting scheme is worked out by using the three-source full storage runoff model and the distributed geomorphologic unit-line，and it is applied to Shuangtian hydrological station，the results of simulation and prediction are good，therefore，the method is applied to the construction of flood forecasting schemes for some small and medium-sized rivers in Jiangxi province.