Regarding gel poly (vinyl alcohol)/H3PW12O40 as precursor, the ultra-fine fibers tungsten oxide (WO3) was prepared by using electrospinning and calcinating techniques. Scanning electron microscope (SEM) shows that the average diameter of fibrous WO3 were changed from 200 nm to 600 nm after calcined PVA/H3PW12O40 fibers at 600 and 800 degrees C, respectively. X-ray diffraction (XRD) and Raman spectroscope revealed that the fibrous WO3 was monoclinic phase, and the band-gap energies were observed by UV-vis diffuse reflectance spectra. The small size WO3 exhibits excellent photocatalytcic activity in degradation of Rhodamine B at 365 nm wavelength. (C) 2011 Elsevier B.V. All rights reserved.