Abstract: Climatic disaster of droughts and floods is one of the most heavy natural disasters in China. It not only has wide distributions and high occurring frequency, but also can cause huge economical losses in China. The studies show that with the global warming, the interannual and interdecadal variabilities of droughts and floods in China become increasingly significant, which is due to the variabilities of the East Asian monsoon climate system including seaairland interaction. Moreover, the future evolution trend of the East Asian summer monsoon (EASM) precipitation for various periods of the 21th century under A1B emission scenary is predicted using IPCCAR4 22 coupled models. The results show that under the background of global warming, the interannual variability of EASM precipitation will be intensified, especially the summer precipitation in North China and South China will become strong from the middle period of the 21th century, which can cause the increase of flood disasters in these regions.