The strict control measures and social lockdowns initiated to combat COVID-19 epidemic have had a notable impact on air pollutant concentrations.According to observation data obtained from the China National Environmental Monitoring Center,compared to levels in 2019,the average concentration of N02 in early 2020 during COVID-19 epidemic has de-creased by 53％,50％,and 30％in Wuhan city,Hubei Province(Wuhan excluded),and China(Hubei excluded),respectively.Simultaneously,PM2.5 concentration has decreased by 35％,29％,and 19％in Wuhan,Hubei(Wuhan excluded),and China(Hubei excluded),respectively.Less significant declines have also been found for SO2 and CO concentrations.We also ana-lyzed the temporal variation and spatial distribution of air pollutant concentrations in China during COVID-19 epidemic.The decreases in PM2.5 and NO2 concentrations showed rela-tively consistent temporal variation and spatial distribution.These results support control of NOx to further reduce PM2.5 pollution in China.The concurrent decrease in NOx and PM2.5 concentrations resulted in an increase of O3 concentrations across China during COVID-19 epidemic,indicating that coordinated control of other pollutants is needed.