Based on the rainfall data from meteorological observation stations in China from 1960 to 2009, the multi time scale complex construction and notably regional differences of annual precipitation variability have been revealed and the precipitation changes in the future also projected according to the interdecadal period. The fluctuant energy of annual precipitation in the northern part of China is larger, and so is the contribution of interannual variation. However， the reality in the southern part of China is reverse. Unlike other regions，the interdecadal variabilities of annual precipitation in the Northeast China and Northwest China are remarkable and in the same phase. At present, the contribution of interdecadal variabilities to the annual precipitation in Northeast China, Northwest China, South China, Tibetan Plateau, and Southwest is in decreasing phase, and tends to keep on going down in the future 5-10 years. However it is in the ascendant phase and tends to keep on rising in the future 5-10 years in the middle and lower reaches of the Yangtze River.