Abstract: Fully mechanized sublevel caving mining method has became main technique used in high-efficiency coal industry in our country. Many new problems occur with fast mining progress, for example, water gushing yield of working face isn t too much than that in traditional method, saying nothing of sudden flood. So hydrogeologic exploration should be done before mining. Distribution of ground-water and forecasted water gushing yield should be ascertained. The paper deals with the study on analysis and forecasting of water gushing yield of bed top in fully mechanized sublevel caving mining from an example of 1302 working face in Xing Longzhuang Mine of Yanzhou Coal Mining Group Ltd. Hydraulics analytic method 3-D finite element numerical simulation is adopted in analysis and forecasting.