Abstract: By using monthly averaged NCEP/NCAR reanalysis data of the atmospheric circulation and the data of summer precipitation in 40 meteorological stations in Shandong province from 1961 to 1998,the climate characteristics of precipitation in the summer of Shandong are analyzed,and the atmospheric circulation anomalies of drought and flood have been compared and analyzed.The result show that the basic precipitation pattern is in phase with each part of the whole province.The summer rainfall is degressive from southeast to northwest of the province.An obvious difference exists with the circulation situation between years of drought and flood.In the years of flood,the East Asia Trough,Ural Blocking High and Western North Pacific Subtropical High are very important systems influencing the summer precipitation.Three warm,wet air currents meet over Shandong and offer plentiful water vapor for precipitation.Opposite situation appears in the above circulation characteristic in the years of drought.