In this paper the research result of the long-range forecast for the Yellow river basin regional rainfall in summer is summarized.On the basis of analyzing the temporal and spatial variation characteristics of the summer rainfall of the Yellow river basin,the summer rainfall is classified by the K-mean cluster.The inter-annual and inter-decadal changes of the summer regional rainfall and their relationship are also calculated and analyzed with lots of associated factors,such as the general circulation at 500hPa,SSTA in the east Pacific,OLR over the tropics,the blocking high in mid-latitudes and the snow cover over Eurasia and the Tibetan Plateau,then an objective numerical forecast system is developed for the summer regional rainfall in the Yellow river basin.The ten years hind-cast of the system shows that the system have fairy good skills in regional rainfall forecast.