In　this　study,　a　series　of　gamma-Fe2O3-modified　V2O5-MoO3/TiO2　(VMT)　catalysts　was　prepared　by　wet　impregnation　method.　The　gamma-Fe2O3-modified　catalysts　exhibited　excellent　catalytic　performance,　and　1.25　wt%　gamma-Fe2O3　content　improved　the　deNOx　efficiency　at　150　degrees　C　from　54%　(unmodified　VMT　catalyst)　to　84%　(modified　catalyst).　BET,　XRD,　XPS,　NH3-TPD,　H2-TPR,　and　in　situ　DRIFTs　were　employed　to　characterize　the　physicochemical　properties　and　reaction　mechanisms　of　the　catalysts.　The　introduction　of　gamma-Fe2O3　increased　the　V5+/V4+　ratio,　surface　chemisorbed　oxygen　content,　redox　ability,　and　a　number　of　acid　sites　in　the　prepared　catalysts.　XPS　confirmed　the　addition　of　gamma-Fe2O3　introduced　new　charge　transfer　pathways　(Fe3+/Fe2+　＜-＞　V5+/V4+).　In　situ　DRIFTs　suggested　that　the　addition　of　gamma-Fe2O3　to　the　catalyst　significantly　increased　the　adsorption　capacity　of　catalyst　for　NH3　and　NOx,　while　also　exerting　a　strong　activating　effect　on　the　adsorbed　NH3.　Furthermore,　selective　catalytic　reduction　over　the　VMT　and　5PEG@1.25Fe-VMT　catalysts　followed　the　Eley-Rideal　(E-R)　mechanism.　At　temperatures　above　200　degrees　C,　the　5PEG@1.25Fe-VMT　catalyst　also　followed　the　Langmuir-Hinshelwood　(L-H)　mechanism.