Based on the basic conditions of surface influence system and of the southwest jet at 700hPa,40 rainstorms in June-Augest from 1983 to 1999 in Qingdao City are classified into three patterns with the method of the synoptic dynamics and statistics:cyclone,typhoon and cold-front.According to the prediction experience,a 0,1 weight equation is obtained to forecast the rainstorm at Qingdao City in summer.For an example,the accuracy of cyclonic rainstorm is 46/59(78.9%).