The TiO2 fibers were prepared by two-step synthesis method: first using tetrabutyltitanate as precursor materials, TiO2 powder was prepared by sol-miniemulsion-gel method, and secondly using synthetic TiO2 powder without heat treatment as raw materials, the TiO2 fibers were prepared by reflux in NaOH solution. The TiO2 fibers were characterized by SEM, TEM, XRD, BET and EDS. The photocatalytic activity of samples was evaluated by photocatalytic degradation of methylene blue. The results indicate that when TiO2 powder is refluxed in NaOH solution with content of 10 mol L-1 and subsequently been heat treatment at 450 degrees C for 2h, the TiO2 fibers are effectively obtained and show high surface areas due to their meshy holes of intertextural structure with rate of length to diameter being about 200. Among catalysts include commercial P25, self-made TiO2 powder and TiO2 fibers with heat treatment at different temperature, they show the highest photocatalytic activity due to high surface areas and optimum crystalline phase. (c) 2007 Elsevier B.V. All rights reserved.