Driven by the global climate model of BCC_CSM1.1, climate change over East Asia in the 21st century is simulated by a regional climate model, RegCM4.0, under the new emission scenarios of RCP (Representative Concentration Pathway). In the present study, the analysis is focused on Yunnan Province and its surrounding areas located in southwestern China. Simulations of present day climate (1986-2005)by RegCM4 are compared against observations to validate the model performance. The results show that RegCM4 can reproduce the observed annual cycle of the regional mean temperature and precipitation well, although a cold bias over the region and an overestimation of precipitation in the dry (cold)season can be found in the simulations. Significant warming and a general decrease of precipitation in both the dry (November to next April)and wet (May to October)seasons in the 21st century are projected by the model under RCP8.5 scenario. The changes show differences in spatial distribution in the two seasons. The drought events are measured by the indices of the maximum number of consecutive dry days (CDD), differences between precipitation and evaporation (P-E), and root zone soil water content (RSW). Analysis of their future changes indicates that the drought will continue and aggravate under the global warming. This is more profound in the dry season compared with the wet season.