Various　control　measures　have　been　proposed　to　reduce　ship　emissions.　However,　improvements　in　air　quality　after　its　implementation　have　rarely　been　evaluated　on　a　regional　scale.　To　fill　this　gap,　this　study　employed　the　Weather　Research　and　Forecast　model　coupled　with　Chemistry　(WRF/Chem)　model　to　investigate　the　improvement　in　air　quality　under　scenarios　separately　implementing　different　control　measures.　The　domestic　emission　control　area　(DECA)　in　the　Pearl　River　Delta　(PRD)　region　of　China　was　selected　as　the　target　area　for　the　study.　The　results　suggest　that　the　use　of　cleaner　fuels　is　a　promising　way　to　improve　air　quality.　For　vessels　sailing　in　the　DECA,　using　0.5%　sulfur-content　fuel　could　reduce　SO2　and　PM2.5　by　0.52　mu　g/m(3)　and　1.43　mu　g/m(3),　respectively,　in　the　target　cities　of　PRD,　while　0.1%　sulfur-content　fuel　could　increase　these　figures　to　0.59　mu　g/m(3)　and　1.62　mu　g/m(3),　respectively.　The　use　of　liquefied　natural　gas　(LNG)　fuel　was　predicted　to　be　the　most　effective　method　for　air　quality　improvement.　LNG　fuel　could　reduce　the　annual　average　concentrations　of　SO2,　NO2　and　PM2.5　by　0.63　mu　g/m(3),　2.80　mu　g/m(3)　and　2.14　mu　g/m(3),　respectively,　in　the　target　cities　of　PRD.　The　application　of　shore　side　electricity　(SSE)　would　reduce　the　ship-contributed　SO2　and　PM2.5　by　0.33　mu　g/m(3)　and　1.06　mu　g/m(3),　respectively.　For　the　NOX　control,　the　retrofit　of　the　selective　catalytic　reduction　(SCR)　system　could　reduce　the　ambient　concentrations　of　NO2　and　PM2.5　by　2.09　mu　g/m(3)　and　0.15　mu　g/m(3),　respectively.　These　results　suggest　that　the　use　of　cleaner　fuels　and　the　retrofit　SCR　system　all　have　positive　effects　on　lowering　the　impact　of　ship　emissions,　while　the　application　of　SSE　could　be　a　useful　supplement.