In this study,based on the simulation results from 18 CMIP5 models,the future changes of the mean and extreme climate in the Belt and Road under three representative concentration pathways(RCP2.6,RCP4.5 and RCP8.5) are projected.The results show that the annual temperature in the Belt and Road would continue to rise in the future as a response to the continuous emission of greenhouse gases,and in addition the rising amplitude tends to increase with the enhancement of greenhouse gas emission.Under the high emission (RCP8.5) scenario,the increase of annual temperature would generally exceed 5℃ by the end of the 21st century,with the greatest warming occurring in West Asia and North Asia,and the smallest in South Asia and Southeast Asia.The annual precipitation is projected to increase over most of the region,particularly in West Asia and North Asia,where the projected increases under the RCP2.6 scenario is greater than that under the RCP4.5 and RCP8.5 scenarios by the middle of the 21st century,while the case is reversed with larger increase in the RCP8.5 scenario than in the RCP2.6 and RCP4.5 scenarios by the end of the 21st century.Extreme temperature is also projected to increase in the future,with the warming amplitude in the high latitudes being greater than in the low latitudes,and that under the high emission scenario greater than under the low emission scenario.Moreover,the increase in the extreme low temperature is greater than that of the extreme high temperature over the high latitudes.The number of consecutive dry days is projected to decrease in North Asia and East Asia,while increasing in other regions.The projected extreme precipitation tends to intensify in the Belt and Road,and the greatest intensification appears in South Asia,Southeast Asia and East Asia.