Air pollution in China has decreased from 2014 to 2019 due to government policies. Most pollutants like PM2.5, PM10, SO2, NO2, and CO decreased, except for O3. Central heating negatively affects air quality. Pollutants are mainly from fossil fuel combustion, industry, and vehicles. North and northwest China have the highest pollutant concentrations. O3 levels are high across the country. Future research should explore meteorological factors and pollutant transformations.