A novel multiwalled carbon nanotube (CNTs) supported vanadium catalyst was prepared. The structure of catalyst prepared was characterized by TEM, BET. FTIR, XRD and temperature-programmed desorption (TPD) methods. The results indicated that vanadium particles were highly dispersed on the wall of carbon nanotubes. The V2O5/CNT catalysts showed good activities in the SCR of NO with a temperature range of 373523 K. The Lewis acid sites on the surface of V2O5/CNT are the active sites for the selective catalytic reduction (SCR) of NO with NH3 at low temperatures. It was suggested that the reaction path might involve the adsorbed NH3 species reacted with NO from gaseous phase and as well as the adsorbed NO, species. The diameter of CNTs showed positive effect on the activities of the catalysts. Under the reaction conditions of 463 K, 0.1 Mpa, NH3/NO = 1, GHSV = 35,000 h(-1), and V2O5 loading of 2.35 wt%, the outer diameter of CNTs of 60-100 nm, the NO conversion was 92%. (C) 2007 Elsevier B.V. All rights reserved.