The　air　quality　modelling　system　WRF-CMAQ　was　applied　to　study　the　sensitivity　of　annual　PM2.5　concentration　to　NH3　emission　control　with　the　scenario　analysis　approach.　The　results　showed　reducing　NH3　emissions　would　lead　to　significant　drop　of　PM2.5,　nitrate　and　ammonium　concentration,　but　relatively　less　impact　on　sulfate　concentration.　And　annual　average　concentrations　of　PM2.5,　nitrate,　ammonium　were　estimated　to　decline　faster　when　emission　of　NH3　are　further　controlled.　The　sensitivity　of　PM2.5　to　NH3　were　0.14,　0.16,　0.19,　0.24　and　0.30,　when　NH3　emission　is　cut　by　20%,　40%,　60%,　80%　and　100%,　respectively,　and　the　concentration　of　PM2.5　would　decline　by　2.7%,　6.3%,　11.3%,　19.0%　and　29.8%　thereby.　Strong　spatial　features　were　observed　on　the　impact　of　NH3　emissions　on　PM2.5　concentration.　Control　of　NH3　would　promote　reducing　PM2.5　pollution　in　regions　with　high　NH3　emission,　such　as　Hebei,　Henan,　Hubei　and　Hunan　Province　and　Chengdu-Chongqing　region.　©　2017,　Editorial　Board　of　China　Environmental　Science.　All　right　reserved.