Titanium substituted SBA-15 mesoporous materials have been successfully prepared by conventional hydrothermal method and they were also used as support on TiO2 loaded SBA-15 photocatalysts. The synthesized materials were characterized by XRD, UV-vis DRS, FT-IR, BET and TEM. We also examined the activity of these materials as photocatalysts for the decomposition of orange II. The incorporation of titanium into framework of SBA-15 makes the pore diameter and pore volume to decrease and slightly decreases the surface area compared to SBA-15. In addition, the pore size distribution becomes broaden with an increase of titanium amount in the SBA-15 framework. For Ti-SBA-15 and TiO2 loaded Ti-SBA-15 photocatalysts, the IR absorption at similar to 960 cm(-1) commonly accepted the characteristic vibration of Ti-O-Si bond. From the TEM images, the regular silica morphology is maintained in the case of Ti-SBA-15(Si/Ti = 50) but the Ti-SBA-15 sample having Si/Ti ratio = 10 partially destroys the hexagonal highly ordered structure and the mesopore structure is disappeared by the clogging of mesopore channels by the titanium dioxides particles for the 50 wt.% TiO2/Ti-SBA-15 samples. The photocatalytic activity increases with an increase of Ti content (decrease of Si/Ti ratio) and with an increase of TiO2 loading content. (C) 2007 Elsevier B.V. All rights reserved.