Based on the integrated simulations of 26 global climate models provided by CMIP5 (Coupled Model Inter-comparison Project),this paper predicted the changes of temperature and precipitation of China in the 21st century under the new representative concentration pathways (RCPs),and analyzed uncertainties of the predictions by Taylor diagram and deviation. Results showed that the increase of average annual temperature of China using three RCPs (RCP2.6,RCP4.5,RCP8.5) was 1.87 ℃,2.88 ℃ and 5.51 ℃,respectively,and the increase of average annual precipitation using the three RCPS was 0.124 mm/d, 0.214 mm/d, and 0.323 mm/d,respectively. The increased temperature and precipitation in the 21st century were mainly contributed by the Tibetan Plateau and the northeast of China. The results of uncertainty analysis showed that most CMIP5 models have a good consistency in predicting the temperature while having a relatively large deviation in predicting the precipitation of China in the 21st century. The deviation analysis showed that more than 80% of the areas of China have greater signals than noises for temperature prediction,but the areas that have meaningful signals for precipitation prediction are less than 20%. Thus, a multi-model ensemble of CMIP5 is more reliable on predicting temperature than precipitation due to the large uncertainties of precipitation.