Heteropoly acids (HPA), such as phosphotungstic acid, are widely used as homogeneous and heterogeneous catalysts because of their good thermal stability, high acidity and high oxidizing ability. In addition, heteropoly acids have high proton conductivity even at a temperature higher than 100 oC. Poly(vinylidene fluoride) (PVDF) is used generally for the advantages of high strength, resistance to solvents, acids, bases. It is easy to process due to its relatively low melting point, low density and low cost compared to the other fluoropolymers. In this study, a composite nanofiber containing PVDF and heteropoly acid is prepared by electrospinning of their mixtures. The nanofibers are characterized by scanning electron microscopy, FTIR, TGA, and XRD. The nanofibers can be used a heterogeneous catalysts for organic reactions. Membranes prepared from the nanofibers can be used as a membrane reactor or a proton conductivity membrane for fuel cells application.