Continuous　aggravated　surface　O3　over　North　China　Plain　(NCP)　has　attracted　widely　public　concern.　Herein,　we　evaluated　the　effects　of　changes　in　aerosols,　precursor　emissions,　and　meteorology　on　O3　in　summer　(June)　of　2015–2019　over　NCP　via　8　scenarios　with　WRF-Chem　model.　The　simulated　mean　MDA8　O3　in　urban　areas　of　13　major　cities　in　NCP　increased　by　17.1%∼34.8%,　which　matched　well　with　the　observations　(10.8%∼33.1%).　Meanwhile,　the　model　could　faithfully　reproduce　the　changes　in　aerosol　loads,　precursors,　and　meteorological　conditions.　A　relatively-even　O3　increase　(+1.2%∼+3.9%　for　24-h　O3　and　+1.0%∼+3.8%　for　MDA8　O3)　was　induced　by　PM2.5　dropping,　which　was　consistent　with　the　geographic　distribution　of　regional　PM2.5　reduction.　Meanwhile,　the　NO2　reduction　coupled　with　a　near-constant　VOCs　led　to　the　elevated　VOCs/NOx　ratios,　and　then　caused　O3　rising　in　the　areas　under　VOCs-limited　regimes.　Therein,　the　pronounced　increases　occurred　in　Handan,　Xingtai,　Shijiazhuang,　Tangshan,　and　Langfang　(+10.7%∼+13.6%　for　24-h　O3　and　+10.2%∼+12.2%　for　MDA8　O3);　while　the　increases　in　other　cities　were　5.7%∼10.5%　for　24-h　O3　and　4.9%∼9.2%　for　MDA8　O3.　Besides,　the　meteorological　fluctuations　brought　about　the　more　noticeable　O3　increases　in　northern　parts　(+12.5%∼+13.5%　for　24-h　O3　and　+11.2%∼+12.4%　for　MDA8　O3)　than　those　in　southern　and　central　parts　(+3.2%∼+9.3%　for　24-h　O3　and　+3.7%∼+8.8%　for　MDA8　O3).　The　sum　of　the　impacts　of　the　three　drivers　reached　16.7%∼21.9%,　which　were　comparable　to　the　changes　of　the　observed　O3.　Therefore,　exploring　reasonable　emissions-reduction　strategies　is　essential　for　the　ozone　pollution　mitigation　over　this　region.　©　2022