Abstract: This study evaluates the performance of two global models, i.e., the NCAR CESM (Community Earth System Model, NCAR) and the CAS ESM (Earth System Model, Chinese Academy of Sciences), for the simulation of boreal summer climate over eastern Asia. Four 19-year (1998-2016) AMIP (Atmospheric Model Intercomparison Project)-type experiments have been conducted using both the NCAR CESM and the CAS ESM with two different horizontal resolutions, and climatological means of 2-m air temperature, precipitation intensity and its diurnal cycle in the boreal summer over eastern Asia are analyzed. The results show that both models can reproduce large-scale features of boreal summer 2-m air temperature and precipitation intensity, although warm biases are found in the simulation of 2-m air temperature and precipitation rate is underestimated. For the diurnal cycle of precipitation, the observed peaks of precipitation occur during the afternoon to early evening over the land and during midnight to early morning over the ocean. Precipitation peaks earlier than observations over the land in the two coarse-resolution experiments, while the nocturnal peak in Sichuan Basin and the morning or early morning peak over some ocean areas cannot be reproduced. Increasing the horizontal resolution can significantly improve the model performance. The two high-resolution experiments distinctly improve the simulation of precipitation peaks over the land and ocean, and can well reproduce the afternoon peak over some islands. Quantitative comparisons between simulations of the two models indicate that the high-resolution CAS ESM experiment can yield the best simulation of precipitation peaks in the entire study region. The simulation of land and sea breezes still needs to be improved. Improvement of physical parameterizations related to precipitation and thermodynamic processes is very important for further improvement of the model performance.