Highly dispersed TiO2/SBA-15 photocatalysts were successfully synthesized by solvothermal treatment using titanium n-butoxide (TB) and carboxylate-modified SBA-15 (COOH/SBA-15) as raw materials. The od dispersive carboxyl groups of COOH/SBA-15 coordinated with TB molecules to anchor them. After solvothermal treatment, the TB molecules were transformed into TiO2 nanoparticles and finally formed the TiO2/SBA-15 products. The products were calcined to improve the crystallization of TiO2 and to remove the organic compounds. As-obtained TiO2/SBA-15 photocatalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption, Fourier transform infrared (FI-IR) spectroscopy, and transmission electron microscopy (TEM). Analytical results showed that the as-obtained TiO2/SBA-15 photocatalysts possessed a better mesoporous structure and a larger specific surface area. The highly crystalline anatase TiO2 nanocrystals dispersed well on the surface of SBA-15. RhodamineB (RhB), as a photodegradation target, was used to evaluate photocatalytic performance under UV light irradiation. The as-obtained TiO2/SBA-15 photocatalysts exhibited much better photocatalytic activity compared with the photocatalysts prepared by a post-synthesis impregnation method.