The mesoporous TiO2 solid and hollow spheres have been synthesized via a controllable and simple chemical route. Structural characterization indicates that these TiO2 mesoporous spheres after calcined at 500 degrees C have an obvious mesoporous structure with the diameters of 200-300 nm for solid spheres and 200-500 nm for hollow spheres. The average pore sizes and BET surface areas of the mesoporous TiO2 solid and hollow spheres are 6.8, 7.0 nm and 162, go M-2/g, respectively. Optical adsorption investigation shows that TiO2 solid and hollow spheres possess a direct band gap structure with the optical band gap of 3.68 and 3.75 eV, respectively. A possible formation mechanism for TiO2 solid and hollow spheres is discussed.