The Huaihe River Basin arearainfall forecast, produced by using the output pre cipitation forecast of the new generation NWP model—GRAPES, is introduced. The t estification with the observation and forecast of forecaster is also made. The co mparison analysis between the two methods and discussions is focused on two per iods when the heavy rainfall led to severe floods in the Huaihe River Basin. One of the periods is from 4 to 11 July 2005, the other from 27 July to 4 August, 2 005. Furthermore, the research on the verification with the observation from rai n gauges is also described. The results show that the GRAPES output precipitatio n forecast is suitable and efficient for making the basin arearainfall for ecast. And by using the high resolution rain gauges data, it is propitious to improve the precision of assessing the basin arearainfall.