MgO-ZrO2 supports with different Mg:Zr ratios (16:1, 8:1, 4:1, 2:1, and 1:1) were prepared by a geloxalate co-precipitation method, and Mg-3(VO4)(2)/MgO-ZrO2 catalysts were then prepared by a wet impregnation method. The prepared catalysts were applied to the oxidative dehydrogenation of n-butane to n-butene and 1,3-butadiene. Experimental results revealed that oxygen capacity and acidity of the catalyst were closely related to the catalytic performance. Among the catalyst tested, Mg-3(VO4)(2)/MgO-ZrO2 (4:1) catalyst, which retained the largest oxygen capacity and acidity, exhibited the best catalytic performance in the oxidative dehydrogenation of n-butane. (C) 2011 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.