Abstract: The photocatalytic materials were synthesized with PAN-based carbon fibers as the support of TiO₂.The carbon fibers were oxidized in 65%-68% nitric acid((115 ℃),) and the TiO₂ was supported on carbon fibers by the method of immersion.The effect of surface oxidation of carbon fibers on its TiO₂ support was studied.The surface of samples was observed by SEM and the bond strength between carbon fibers and TiO₂ support was evaluated by ultrasonic vibration.The results suggested: the ratios of TiO₂ support both before and after ultrasonic wash increased with oxidation time.For overall consideration of factors in the treatment,it is indicated that when carbon fibers is oxidized for 4 h the better effect of TiO₂ support can be obtained.