A regional climate model (RegCM4) is employed to investigate the impacts of land use/cover change (LUCC) on the climate over the eastern part of Northwest China (ENW) in the periods of 2001 and 2011. To distinguish the actual effect of LUCC from random errors caused by individual case selection, the climate effects of LUCC are analyzed based on two groups of multi-year RegCM4 ensemble simulations, using the land cover data of 2001 and 2011, respectively. The results indicated that the LUCC in ENW, which was characterized by desert retreat, reforestation, and farmland expansion, led to significant local changes in surface air temperature (within ~0.3°C) and slight regional changes in precipitation (within ~15%) in summer. In the desert retreat area, the net absorbed shortwave radiation had a greater influence than evaporative cooling, leading to increases in the daily mean and maximum temperature. Besides, the daily mean and maximum temperatures increased in the reforestation area but decreased in the farmland expansion area. As surface albedo showed no significant change in these regions, the temperature increase in the reforestation area can be attributed to a decrease in evaporation, while the opposite effect appears to have been the case in the farmland expansion area.