A composite nanofiber containing poly(vinylidene fluoride) (PVDF) and phosphotungstic acid (PWA) is prepared by electrospinning of their mixtures. The nanofibers are characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction spectroscopy (XRD). The spun nanofibers are in the p phase of PVDF and are bead-free in structure. Membranes prepared from the nanofibers can be used as a proton conductivity membrane for fuel cell applications. (C) 2009 Elsevier Ltd. All rights reserved.