Abstract: By using the regional climate model (NCC/RegCM), two modeling experiments were undertaken to investigate the regional climate change by changed vegetation in China, and results indicate that vegetation changes in large regions have notable effect on regional rainfall and temperature: desertification in Inner Mongolia results in rainfall decreasing in many regions, especially in north China and northwest China. On the contrary, reforestation in northwest China leads to rainfall increasing in Yellow River basins, but rainfall decreasing to different degree over Yangtze River basins and south China in summer, and hence, conduce to less flood occurrence over there. The effects to temperature is more significant, with temperature remarkable increasing over the desertification region, as well as wind on lower layer enhancing, as a result, the local climate becoming drier and unfavorable for vegetation regrowing. But in the reforestation region, local air temperature become warmer in winter and cooler in summer, with more moisture supplying to atmosphere and lower wind decreasing, thus may be reduce dust storm weather in some degree. On the other hand, vegetation changes also have obviously effects on the intensity of East Asian summer and winter monsoon, so tends to influence the rainfall distribution over East China and the occurrence of low temperature damages in winter. 