Power　plants　remain　major　contributors　to　air　pollution,　and　while　their　impact　on　air　quality　and　atmospheric　chemistry　have　been　extensively　studied,　there　are　still　uncertainties　in　quantifying　their　precise　contributions　to　PM2.5　and　O-3　formation　under　varying　environmental　conditions.　This　study　employs　the　WRF/CMAQ　modeling　system　to　quantify　the　impact　of　power　plant　emissions　on　PM2.5　and　O-3　levels　across　eastern　China　in　June　2019.　We　investigate　the　spatial　and　temporal　patterns　of　pollutant　formation,　analyze　contributions　to　secondary　PM2.5　components,　and　assess　process-specific　influences　on　O-3　concentrations.　Results　show　that　power　plant　emissions　contribute　up　to　2.5-3.0　mu　g　m(-3)　to　PM2.5　levels　in　central　and　eastern　regions,　with　lower　impacts　in　coastal　and　southern　areas.　O-3　contributions　exhibit　a　more　complex　pattern,　ranging　from　-4　to　+4　ppb,　reflecting　regional　variations　in　NOx　saturation.　Among　secondary　PM2.5　components,　nitrate　formation　is　most　significantly　influenced　by　power　plant　emissions,　emphasizing　the　critical　role　of　NOx.　Diurnal　O-3　patterns　reveal　a　transition　from　widespread　morning　suppression　to　afternoon　enhancement,　particularly　in　southern　regions.　Process　analysis　indicates　that　vertical　transport　is　the　primary　mechanism　enhancing　surface　O-3　from　power　plant　emissions,　while　dry　deposition　acts　as　the　main　removal　process.　This　comprehensive　assessment　provides　crucial　insights　for　developing　targeted　air　quality　management　strategies,　highlighting　the　need　for　region-specific　approaches　and　prioritized　NOx　emission　controls　in　the　power　sector.　Our　findings　contribute　to　a　deeper　understanding　of　the　complex　relationships　between　power　plant　emissions　and　regional　air　quality,　offering　a　foundation　for　more　effective　pollution　mitigation　policies.