Mesoporous titania with an average pore diameter of 2.6 nm and rutile crystalline structural wall was prepared by hydrolyzing TiOCl2 aqueous solution at lower temperature by using octyl polyethylene oxide surfactant as template-directing agent. The mesoporous structure of as-synthesized mesoporous rutile titania consisting of self-assembled nano crystals keeps stable after the removal of the surfactant by acetone extraction and following UV irradiation. The mesoporous rutile titania exhibits a good photocatalytic activity for gas-phase photo-oxidation of a mixture of benzene and methanol. A mechanism of self-assembly of nano titania crystals is proposed to explain the formation of mesoporous rutile titania. (C) 2004 Elsevier B.V. All rights reserved.