Mesoporous VOx /SBA-15 catalysts with different V contents were evaluated for the oxidative dehydrogenation of n-butane and characterized by N-2 adsorption, XRD, HRTEM, H-2-TPR, NH3-TPD, XPS, and EPR techniques. Compared to conventional V2O5/SiO2 catalysts, the VO (x) /SBA-15 catalysts showed better performance. The good performance can be attributed to the good dispersion of V species, presence of V4+ species and the pore structure.