Abstract: In this paper,predictability experiments are run of monthly rainfall using samples of time series for the past 100 years in Kunming.It is concluded with estimation and 144 independent prediction experiments using 12 years of data that with proper requirement on forecast accuracy,the time scale for predictable monthly rainfall is about 5 months;for the number of Dimension m in the phase space properly embedded and the time scale T in reasonable advancement,the prediction of anomalous sign is 60% correct for the monthly rainfall and 65% correct in rainy season(May-October).