Porous carbon nanofibers (CNFs) were fabricated from poly(vinyl alcohol) (PVA). The precursor nanofibers prepared by electrospinning an aqueous solution of PVA, diammonium hydrogen phosphate (DAP) and sodium dodecyl sulfate (SDS) were transformed into CNFs by stabilization through intramolecular dehydration of PVA induced by DAP, followed by carbonization in N-2. The fiber diameters of the CNFs were controllable by the SDS concentration. During the stabilization and carbonization processes, salt particles were produced inside of the fibers because of the decomposition of SDS and DAP. By leaching the particles with water, ink-bottle-type spherical macropores with diameters of approximately 100 nm were formed, whose pore volume depended on the SDS concentration. The performances of CNFs as electrodes of electric double layer capacitors were investigated by cyclic voltammetry. The CNF with larger macropore volume reduced the deterioration of specific capacitance at the high voltage scan rate owing to the enhanced accessibility to the surface. (C) 2016 Elsevier Ltd. All rights reserved.