Based　on　CNFs　supports,　a　series　of　MnO2/CNFs　catalysts　were　synthesized　by　a　liquid　phase　coprecipitation　method,　and　it　was　applied　to　selective　catalytic　reduction　(SCR)　of　NO.　The　microstructure,　elemental　composition,　and　valence　state　of　the　as-obtained　catalysts　were　characterized　by　BET,　XRD,　FESEM,　EDS,　XPS　and　TEM.　The　results　show　that　MnO2　is　distributed　on　the　surface　of　CNFs　with　amorphous　form　equably　as　the　active　components.　MnO2/CNFs　catalyst　shows　up　the　best　activity　in　the　test　of　SCR　at　the　testing　temperature　range　of　80-180,　when　the　loading　amount　is　6%.　NO　transformation　rate　is　65.25%　at　80,　and　95.25%　at　180.　Amorphous　structure,　favorable　dispersion　and　higher　content　of　surface　oxide　are　the　main　cause　of　MnO2/CNFs＇s　excellent　catalytic　activity　at　low　temperature.　MnO2　is　loaded　on　the　CNFs　without　any　acid-treated,　which　makes　it　more　environment-friendly.　©　2018,　Journal　of　Materials　Engineering.　All　right　reserved.