A new Ni-V-Sb/gamma-Al2O3 catalyst is proposed for the oxidative dehydrogenation of ethylbenzene. A study has been made of the catalytic activity of its individual components supported by gamma-Al2O3. It has been shown that the Ni-V/gamma-Al2O3 and V-Sb/gamma-Al2O3 systems differ little in activity. This fact as well as coking of the surface of the Ni-V-Sb/gamma-Al2O3 catalyst during the reaction, levels out any variations in activity of specimens prepared in different ways, which makes the oxidative dehydrogenation of ethylbenzene substantially different from that of n-butane on a Ni-V-Sb/gamma-Al2O3 system. A study has been made of the kinetic relationships, and it has been shown that the mechanism of the main process includes the formation of oxidative condensation products. Intradiffusional retardation of extensive degradation of ethylbenzene has been found.