The mesoporous TiO₂ thin film was synthesized by spin-coating method from C₁₆EO₂₀ as a structure-directing agent. The mesophase was strongly affected by the solvent evaporation period, exhibiting the best structural integrity after 3 days of aging at 40 ℃ in open beaker. The XRD pattern and TEM image showed that a well-ordered cylindrical pore structures were formed, which can be indexed in a 2D hexagonal (p6m) or 2D centered-rectangular cell (c2m) in the direction normal to the surface. The UV/Vis. absorbance of mesostructured TiO₂ film was larger in short wavelength below 300 nm than that of amorphous film. Moreover, the photocurrent response of mesostructured TiO₂ film was larger than amorphous film, which indicates that high surface ares, structural regularity of mesophase, which the distinct order on mesoscopic scale (long range) of titania is affect somewhat to the photoelectronic property as well as order on the atomic scale (short range).