This paper presents a dynamical downscaling simulation of future climate using the Weather Research and Forecasting (WRF) model and projects the climatic changes under the IPCC SRES A1B scenario over China in the middle (2041-2060) and at the end (2081-2100) of the 21st century. In the middle of the 21st century, the annual mean surface air temperature over most parts of China would increase by 2-4℃ compared to the present, with the largest temperature increases over North China and the Tibetan Plateau. Precipitation over Northwest China and the area between the middle and lower reaches of the Yellow River and the Yangtze River would increase, with precipitation over South China and most parts of Northeast China remaining stable or even decreasing somewhat. The standard deviation of the mean temperature in the northern part of China is larger than that in the southern part, and the largest value appears over the Tibetan Plateau. This means that the interannual temperature variations in northern China would be more obvious than those in southern China, with the largest variations over the Tibetan Plateau. Large interannual variations in precipitation are projected, mainly over North and Northwest China. At the end of the 21st century, the annual mean surface air temperature over most parts of China would increase by more than 4℃ compared to the present, and the largest temperature increases would still be over North China and the Tibetan Plateau. An average temperature increase of more than 7℃ would be seen in most parts of the Tibetan Plateau region. Furthermore, winter and spring temperatures would increase more than summer and autumn temperatures at the end of the 21st century. On the whole, precipitation would increase in most parts of China, except for a few areas in southern China. The interannual variation in the mean temperature in northern China would still be larger than that in southern China, with the largest value over the Tibetan Plateau. North and Northwest China would still experience large interannual variations in precipitation.