In　recent　years,　the　ozone　(O3　)　volume　fraction　in　the　Beijing-Tianjin-Hebei　Region　in　summer　have　remained　high,　light　to　moderate　pollution　occurs　frequently,　and　research　on　related　response　mechanisms　is　urgently　needed.　This　study　applied　the　WRF-Chem　model　to　simulate　the　change　in　ozone　volume　fraction　in　this　region　by　setting　13　precursor　emission　scenarios　in　a　representative　month　in　the　summer　of　2018.　The　results　revealed　that　VOC-sensitivity　and　no-sensitivity　regimes　commonly　occurred　in　the　Beijing-Tianjin-Hebei　Region　in　July,　and　the　VOC-sensitivity　regimes　were　mainly　accumulated　in　the　central　Beijing-Tianjin-Hebei　Region,　with　a　north-to-south　zonal　distribution　and　an　area　share　of　15.　60%-26.　59%.　The　relative　response　intensity　(RRI)　of　O3　volume　fraction　to　precursor　emissions　in　urban　areas　had　large　spatial　variability,　with　RRI_VOC　and　RRI_NOx　in　the　ranges　of　0.　03-0.　16　and　-0.　40-0.　03,　respectively.　The　higher　the　latitude　of　urban　areas,　the　more　dramatic　were　the　RRI　values,　indicating　a　more　significant　regional　transport　influence.　The　lower　RRI_NOx　values　in　urban　areas　with　high　intensity　of　precursor　emissions　implied　a　negative　dependence　of　RRI_NOx　on　local　NO2　concentrations;　however,　RRI_VOC　was　not　significantly　correlated　with　NO2　levels　and　was　more　dependent　on　the　relative　abundance　of　precursors　(VOCs:　NOx　).　The　ratio　of　RRI_VOC　to　RRI_NOx　showed　negative　values　in　majority　of　the　cities;　therefore,　collaborative　VOCs　emission　reduction　is　necessary　to　suppress　the　deterioration　of　O3　volume　fraction.　The　absolute　value　of　this　ratio　was　much　lower　in　cities　with　high　industrialization　and　urbanization　than　in　ordinary　small　and　medium-sized　cities,　implying　that　the　demand　for　collaborative　VOCs　emission　reduction　in　these　cities　will　be　higher.　However,　even　under　50%　reduction　of　precursors,　the　improvement　in　O3　volume　fraction　was　limited　in　regional　cities,　and　the　combined　prevention　in　neighboring　cities　remains　important.　©　2023　Science　Press.　All　rights　reserved.