Mesoporous silica microsphere was prepared by microwave hydrothermal synthesis，using hexadecyl trimethyl ammonium bromide (CTAB) as template agent and tetraethylorthosilicate (TEOS) as silica source. And mesoporous silica microspheres doped with TiO2 was prepared by sol-gel method. They were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (IR) and N2 adsorption-desorption analysis. Then methylene blue decoloration test was investigated to verify the mechanism proposed elsewhere, with respect to concentration, amount of samples, pH and light illumination. Results indicate that low concentration, large amounts of samples, alkaline and UV illumination are more favorable to adsorption, and TiO2/MSM has higher decoloration rate than MSM.