In order to improve the repeating circles of the semiconductor titania photocatalyst and broaden its applications, thin film coatings of titania based on polyacrylonitrile, fibers (TiO2/PAN) were prepared successfully at room temperature by a simple dip-coating method. Titania nanocrystals were prepared by a low temperature dissolution-reprecipitation process in a liquid media using TiCl4 as precursor, and the crystallization of amorphous precursor was proceeded by peptizing with acid and then refluxing for a periodic time. The films had been characterized by XRD, UV-vis, SEM and the photocatalytical properties of the titania films had been testified by the photodegradation of methylene blue (MB). SEM images showed the information of continuous layers of titania on PAN fibers, XRD patterns revealed the main phase of the titania particles and titania coatings were anatase. UV-vis analyses revealed the coated titania produced an excellent UV protection of the coated fiber. The fibers with anatase coatings showed high photocatalytic property and better repetition on the photodegradation of MB. The titania coated fibers are expected to be applied as a novel antibacterial, deodoring and antifouling photocatalyst. (c) 2005 Elsevier B.V. All rights reserved.