Based on an acidolysis reaction between titanium n-butoxide and carboxyl (COOH) groups, serial highly dispersed TiO 2 photocatalysts were successfully synthesized on COOH-modified mesoporous SBA-15 material. Even after calcined at 550°C to improve the crystallization, the TiO 2 /SBA-15 products possessed high surface area above 400m 2 g −1 that should be attributed to the high porosity of mesoporous SBA-15 and the highly uniform COOH group distribution in mesopores. HRTEM images revealed that TiO 2 nanocrystals dispersed well on the surface of SBA-15. The pore channels were partly blocked by TiO 2 nanocrystals, resulting in a bimodal pore size distribution in TiO 2 /SBA-15 compared with SBA-15. XRD and Raman results disclosed the exclusive anatase phase of TiO 2 in the photocatalysts. With adjusting the molar ratio of COOH to TB, the TiO 2 /SBA-15 products displayed different photocatalytic performance using Rhodamine B as probe under UV light.