A　WRF-CAMx-PSAT　model　was　applied　to　analyze　the　impact　of　the　electric　power　industry　on　urban　agglomerations　along　the　middle　reaches　of　the　Yangtze　River.　A　high-resolution　emission　inventory　based　on　a　bottom-up　approach　was　developed　for　air　quality　simulation.　A　typical　month　with　heavy　air　pollution　in　this　region　(i.e.,　January)　was　chosen　for　simulation,　and　two　mitigation　scenarios　were　set　for　assessing　lower　capacity　power　units＇　impact　on　regional　air　quality.　One　scenario　was　for　shutting　down　the　lower　capacity　power　units,　and　the　other　was　for　replacing　lower　capacity　power　units　with　higher　capacity　power　units.　Results　showed　that　lower　capacity　power　units　contributed　bigger　pollutant　concentrations　to　the　regional　contribution　of　the　electric　power　industry.　The　concentration　contributions　of　SO2,　NOx,　and　PM2.5　in　the　two　mitigation　scenarios　were　reduced　by　36.2%-39.8%,　30.5%-33.5%,　and　25.9%-30.7%,　respectively,　than　those　under　the　current　situation.　Meanwhile,　the　decreases　in　pollutant　concentration　contribution　for　different　regions　were　very　similar　for　the　two　mitigation　scenarios.　In　addition,　lower　capacity　power　units　in　four　regions　(i.e.,　northwest　of　Hubei　province,　west　of　Hunan　province,　Xiang-Jing-Yi　economic　belt　region,　and　Hefei-centered　urban　agglomerations)　contributed　obviously　to　the　regional　pollutant　concentration　contributions　of　the　electric　power　industry.　Regional　pollutant　concentration　contributions　in　the　two　mitigation　scenarios　were　reduced　by　40%-70%.　Therefore,　lower　capacity　power　units　make　a　bigger　impact　on　the　air　quality　of　urban　agglomerations　along　the　middle　reaches　of　the　Yangtze　River　and　should　be　paid　special　attention　to　achieve　better　regional　air　quality.　©　2018,　Science　Press.　All　right　reserved.