Mesoporous titanium dioxide spheres were synthesized by a convenient solvothermal method at room temperature with tetraethyl titanate as a precursor. Investigation by means of X-ray diffraction（XRD）, transmission electron microscopy（TEM）, scanning electron microscopy（SEM）, and N2 adsorption-desorption isotherms confirms that the sample has a mesostructure with a higher specific surface area and shows that the mesoporous TiO2 spheres have a diameter of 2 μm, the average pore size is about 5.9 nm, and the BET surface area and specific pore volume are about 236 m2/g and 2.116 cm3/g, respectively. The anatase and rutile mesoporous TiO2 spheres calcined at 700 °C show much better photocatalytic activity than the samples calcined at other temperatures and is comparable to an uncalcined sample in the photodegradation of Methyl Blue（MB） under the UV irradiation.
