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An increase in the propylene output in the oxidative dehydration of propane on V 2 O 5 /TiO 2 -SiO 2 was observed after prior reduction of V 2 O 5 in the reaction mixture to V 2 O 4 , which reduces the destructive chemisorption of propylene. A low titanium dioxide content in TiO 2 -SiO 2 hinders the deep reduction of V 2 O 5 to V 2 O 3 , which reduces the conversion of propane. Key words: propylene adsorption, vanadium oxide, oxidative dehydrogenation of propane.The oxidative dehydration (ODH) of propane to give propylene is currently the subject of extensive investigation in work designed to replace the high-temperature dehydrogenation of propane, which requires the periodic regeneration of the coked Cr 2 O 3 /Al 2 O 3 catalyst in the air by dehydrogenation in the presence of oxygen in the reaction mixture [1, 2]. The search for propane ODH catalysts has been undertaken in many laboratories but the results obtained so far do not hold industrial interest. The best propane yields are 35 mole % and have been obtained on vanadium-containing oxide systems on supports, which have a significant effect on the properties of the active phase [3,4].The dehydrogenation of propane in the presence of oxygen may be seen as a combination of two reactions [5]: the reversible endothermal removal of hydrogen C 3 H 8 « C 3 H 6 + H 2 , DH = 124.3 kJ/mol and the exothermal oxidation of hydrogen H 2 + 0.5O 2 ® H 2 O, DH = -241.8 kJ/mol, which shifts the equilibrium of the first reaction toward the formation of propylene.