Polypyrrole (PPy)/polypropylene fibrous membrane (PPF) composite materials with different PPy contents are prepared through in situ chemical oxidation polymerization in the pyrrole atmosphere at room temperature by dissolving the FeCl(3)center dot 6H2O in methanol and acetonitrile as oxidant. The morphology of the composite is examined by scanning electron microscope (SEM), the conductivities of the composites are measured by convenient four-probe method, and the properties of the capacitor cells assembled by the obtained PPy/PPF are investigated by cyclic voltammetry (CV), galvanostatic charge/discharge, and electrochemical impedance spec-troscopy (EIS) measurements. The results show that the morphology, conductivity, and the capacitor property of the composite are influenced strongly by the solvent of the oxidant. The capacitor assembled by the PPy/PPF prepared by using acetonitrile as the solvent for FeCl(3)center dot 6H2O can adapt for quick charge/discharge, and exhibit the highest capacitance of about 72.5 F g(-1) when the PPy content is about 8.0%. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 3415-3422, 2011