This study took the Chaihe River basin as the research area using the TIGGE data. The short-term precipitation of 6h，12h and 24h from ECMWF， NCEP and UKMO were taken into quantitative evaluation and comparison by using the methods of TSscore， Brier score and Talagrand distribution. And then the Xinanjiang model was driven to simulate the flood process with the actualrainfall and NCEP rainfall forecasting respectively. The availability of ensemble forecast was discussed and the results showthat： （1） The ECMWF， NCEP and UKMO are better for rainfall forecast with low precipitation， and the forecast effect of eachrainfall level increases with the forecast period， and in general， the empty reporting rate is higher than the omissive judgementrate. （2） The data of ensemble forecast can be applied to the flood forecast of Xinanjiang model， and can effectively extend theforecast period of flood forecast. Therefore， the research results could be applied to flood forecasting in the other basins.