Region-oriented simultaneously joint two-pollutant control strategies are required to substantially reduce deaths attributed to both PM_2.5 and ozone pollution in China

China is confronting serious air pollution of fine particulate matter (PM_2.5) and ozone, which routinely exceed air quality standards. PM_2.5 concentrations decreased by 30–40% while ozone increased by 15–20%, across China during 2015–2019. This could be attributed to targeted clean air policies that have focused more on controlling particulate matter since 2013. The deaths attributable to PM_2.5 and ozone exposure over China changed from 1.45 to 0.13 million in 2015 to 1.04 and 0.21 million in 2019, respectively. The changes in mortality, PM_2.5 and ozone present spatially heterogeneous patterns across cities and regions. The ozone production regimes (NO_x -limited, volatile organic compounds (VOCs)-limited or transition between them), the responses of P(O₃) to the change in NO_x and VOCs, the reactions of HO₂, OH, and RO₂, and meteorological conditions, are regionally dependent and spatially heterogeneous. Our results have important implications for developing a smarter, region-oriented, two-pollutant coordinated control policy for VOCs and NO_x in China.