The TiO2/hydroxylapatite (TiO2/HA) composite with 6.0% HA molar content was prepared by precipitation method and heat-treatment at 500 degrees C for 40 min. The products were charactered by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The sonocatalytic activity of the prepared TiO2/HA composite was studied through the damage of bovine serum albumin (BSA) in aqueous solution under ultrasonic irradiation. The effects of several factors on the sonocatalytic damage of BSA molecules were evaluated by means of UV-vis and fluorescence spectra. It was found that the damage degree was aggravated with the increase of ultrasonic irradiation time, ultrasonic irradiation power. TiO2/HA addition amount, solution acidity and ionic strength. The damage site to BSA molecules was also studied using synchronous fluorescence technology. It was observed that the damage site was mainly focused on the tyrosine (Tyr) residue of BSA molecule. These research results are of great significance for driving sonocatalytic method to treat tumor in clinic application. (C) 2011 Elsevier B.V. All rights reserved.