Alumina-supported vanadium oxide catalysts (V2O5 similar to 10 wt.%) with and without SnO2 were tested in the dehydrogenation of isobutane at 590degreesC under atmospheric pressure and were characterized by BET, XPS, TPR, XRD and RAMAN. It is found that the electron interaction exists between V and Sn oxide species on the surface of support. The doping of appropriate amount of SnO2 leads to that the surface vanadia of catalysts is more reduced and is more highly dispersed than undoped catalyst. V2O5/gamma-Al2O3 catalyst with 3 wt.% of SnO2, exhibited higher reactivity in dehydrogenation of isobutane to isobutene. (C) 2004 Elsevier B.V. All rights reserved.