Isobutane dehydrogenation was studied on chromia supported on mixed oxides of silica and titania catalysts. The catalyst supports, silica-titania mixed oxides, were prepared by three different methods : a modified sol-gel method, a mechanical mixing of silica and titania, and a calcination of tetraethyl orthosilicate (TEOS) intercalated crystalline titanate : Chromia supported on the mixed oxide (Si:Ti mole ratio = 0.36) prepared from TEOS intercalated crystalline titanate is the most active among these chromia supported mixed oxide catalysts. The isobutylene yield of this catalyst was about 60% of Girdler G-41 catalyst, comparable to that of the in-house chromia/gamma-alumina catalyst, 2 times as much as that of the chromia/titania catalyst, and 6 times as much as that of the chromia/silica catalyst.