According to the study on synthetic medium and long-term hydrologic forecasting for Xiaoshan, Songshan and Liangjiang hydropower station situated on the upper reaches of Second Songhuajiang River, the consideration of study on synthetic medium and long-term hydrologic forecasting and the method of qualitative and quantitative runoff forecasting is introduced in this paper. Through applying the study in 2002, the result shows that the achievement is applicable.