The kinetics of the liquid-phase oxidation of cyclooctene by molecular oxygen catalyzed by VB2 on initial stages of process was studied. The vanadium diboride was found to activate the oxidation process in the presence of hydroperoxide in the reaction system. It was shown by FIR investigation that cyclooctene and hydroperoxide are complexed with the same catalytic center. The reaction rate depended on cyclooctene concentration with less than first order. In the investigation system the radicals are formed as a result of proceeding of two processes-noncatalytic and catalyzed by vanadium diboride bimolecular decomposition of tert-butyl hydroperoxide. Based on the obtained data the kinetic model of the investigated process was proposed. The equation for the reaction rate was derived from this model. This equation is allowed to describe all observed kinetic dependences. (C) 2008 Elsevier B.V. All rights reserved.