By using 65 station daily precipitation data provided by the China Meteorological Administration and NCEP reanalysis data, this paper discussed the interdecadal change of the precipitation and the clustered extreme precipitation event in South China. Main conclusions are as follows: The precipitation in South China has experienced an obvious interdecadal change in 1991/1992, during this period, atmospheric circulation also shows a significant shift, including an intensity decrease and northward shift for the westerly jet over east Asia, an eastward shift for the northwest Pacific subtropical high, increases in the convergence at low level, the divergence at high level, the upward movement and the convergence for the water vapor transport. In addition, the water vapor transport associated with extreme precipitation is also different from the mean condition. During extreme precipitation events, water vapor transmission in the Indian Ocean and northwest Pacific is more than mean condition. In the case of heavy rainfall events, the increase of water vapor is mainly due to northwest Pacific and the south China sea. Further analysis indicated that water vapor transmission increased in the Indian Ocean after 1991/1992, while water vapor in the northwest Pacific decreased. This finding is a good illustration of the important changes in the concentration of precipitation in southern China since 1991/1992.