SiO 2 /TiO 2 composite microspheres with microporous SiO 2 core/mesoporous TiO 2 shell structures were prepared by hydrolysis of titanium tetrabutylorthotitanate (TTBT) in the presence of microporous silica microspheres using hydroxypropyl cellulose (HPC) as a surface esterification agent and porous template, and then dried and calcined at different temperatures. The as-prepared products were characterized with differential thermal analysis and thermogravimetric (DTA/TG), scanning electron microscopy (SEM), Xray diffraction (XRD), nitrogen adsorption. The results showed that composite particles were about 1.8 mm in diameter, and had a spherical morphology and a narrow size distribution. Uniform mesoporous titania coatings on the surfaces of microporous silica microspheres could be obtained by adjusting the HPC concentration to an optimal concentration of about 3.2 mmol L Γ1 . The anatase and rutile phase in the SiO 2 /TiO 2 composite microspheres began to form at 700 and 900 1C, respectively. At 700 1C, the specific surface area and pore volume of the SiO 2 /TiO 2 composite microspheres were 552 and 0.652 mL g Γ1 , respectively. However, at 900 1C, the specific surface area and pore volume significantly decreased due to the phase transformation from anatase to rutile.