The GEOS-Chem model was applied to examine the effects of changes in anthropogenic emissions and meteorological parameters on the changes in summertime OH concentrations in China since the implementation of the Air Pollution Prevention and Control Action Plan. Our modeling results over years of 2014–2017 show that summertime OH concentrations in China exhibited an overall upward trend with the fastest increases around the 30°N over eastern China; the North China Plain was also simulated having an obvious upward trend of OH concentration of 0.1×106 molec cm?3/year, while the Pearl River Delta experienced a weak trend. Further sensitivity experiments simulations showed that changes in both meteorology and anthropogenic emissions over 2014–2017 contributed to the increases in OH concentrations in the North China Plain, in which the contribution of anthropogenic emissions was significantly larger than that of meteorology (10% vs. 1.5%); Meteorology played a dominated role in OH increase around 30°N over eastern China. Our further meteorological analysis shows that the meteorological variable with the greatest contribution was solar shortwave radiation, which can explain the OH changes over a large fraction of China during 2014–2017. However, the role of solar shortwave radiation was offset by the boundary layer height in affecting 2014–2017 OH changes in the North China Plain.