The　Cl-V2O5-WO3/TiO2　catalysts　were　prepared　by　impregnation　methods.　With　the　Cl　ions　content　increased　from　0　to　2.5%,　the　NO　conversion　of　Cl-V2O5-WO3/TiO2　catalysts　increased　at　first　and　then　decreased.　Combined　with　the　experimental　results,　1.5%　Cl-V2O5-WO3/TiO2　catalyst　was　the　optimal　catalyst,　NO　conversion　was　higher　than　95%　in　the　range　of　149-362,　and　NO　conversion　was　higher　than　90%　in　the　temperature　range　of　145-385.　The　catalysts　were　characterized　by　XRF,　BET,　XRD,　TG,　FT-IR　and　H2-TPR.　The　specific　surface　area　and　pore　volume　of　the　catalysts　decreased　in　different　degrees　after　adding　SO2　and　H2O　in　reactant　gas.　The　poisoned　catalysts　deposited　sulfur　species　and　contained　NH4+　and　SO42-.　Adding　appropriate　amount　of　Cl　ions　inhibited　the　formation　of　side　byproducts　and　enhanced　the　poisoning　resistance　of　V2O5-WO3/TiO2　catalyst.　©　2018,　Science　Press.　All　right　reserved.