The process of the weather conditions from drought to rain in Shandong Province in June 1994 is summed up. The results show that the key factors for the successful prediction of the important change lies mainly on the understanding and mastering of the effect of the westerly on the change of subtropical high,and the Pacific ocean,the grasping of the feature of circulation which makes the subtropical high turn suddenly to the north-west,and the use of the factors of experience,NWP the objective forecasting method coordinately.