This paper gives the general situation of the Huaihe River Basin,the flood forecasting system for the main stream of the Huaihe River and the forecasting method.In the flood forecasting for main stream of the Huaihe River in 1991,rainfall runoff forecasting was combined with the corresponding discharge forecasting at the downstream and up-stream stations, and real time flood information anslysing was paid attention to. As concerned as for the runoff concentration calculation for the reaches with more flood ways ,wide water surface and small slope after flooding,lake flood routing method was used based on the experiential channel storage curve which was drawn with the observed flood data.the great success was achieved in the forecasting for the two great floods in the main stream of the Huaihe River, which provided scientific basis for the decision making of flood prevention. the full utilization of the flood ways and flood storage basins according to the flood forecasting effectively decreased the water level of the flood peak in the main stream of the Huaihe River,which ensured safety of flood prevention and reduced flood disasters.