The reaction of methylcyclohexane dehydroalkylation by methanol on modified forms of mordenite and pentasil was studied. The kinetic features of the process in the presence of HNa-pentasil modified by gallium and iron oxides and phosphorus were investigated. A kinetic model that fairly well describes the process at 430-570 degrees C is suggested. The reaction mechanism is considered, which involves the dehydroalkylation of methyl-cyclohexane by methanol via the intermediate dehydrogenation of both hydrocarbons and alcohol and the subsequent interaction of the unsaturated compounds formed with formaldehyde adsorbed on the catalyst surface.