Rainfall station network is one of the extremely important components for hydrological station network, and the precisionof flood forecast is directly affected by the accuracy and representative of rain-gauge data. Thus, in order to better improve theprecision of flood forecast, it is vital to scientifically plan and optimize the rainfall station network to make rain-gauge data reflectsthe actual rainfall in the region as exactly as possible. Based on the current development of hydrological technology, this paperadopted reducing rain-gauge station method and GIS technology, and took underlying surface factors like landform, weather andstationing into account, to optimize a rain-gauge network of the experimental region in Jiangxi Province.