Using European Centre for Medium Range Weather Forecasts numerical forecast grid materials and precipitation materials in six weather stations from 1996 to 2008 and precipitation materials of 47 encryption automatic region stations from 2007 to 2008 in Shiyang River basin,forecast factors were initially elected with Press criterion and forecast factors were precisely selected with stepwise regression method,1 to 7 day precipitation prognostic equations of cold and warm season were built with optimal subset ...