The capabilities of 46 CMIP5 (the Coupled Model Intercomparison Project Phase five) models for simulating the annual, summer, and winter precipitation climatology over China are first examined using the outputs of these models from historical data for the period 1986-2004. Eighteen models are then chosen to project the changes of monsoon area, monsoon precipitation, and monsoon precipitation intensity over China under the Representative Concentration Pathways 4.5 (RCP4.5) scenario. The results show that the monsoon area, monsoon precipitation, and monsoon precipitation intensity will increase in the 21st century, particularly during 2081-2099. The increase in the monsoon precipitation is mainly derived from the increase in the monsoon area. Both thermal and dynamic conditions will be favorable for increased monsoon precipitation intensity and greater water vapor transport into eastern China, resulting in the expansion of the monsoon area in China.