The homogenous proton conducting WO3/PFSA membranes are prepared based on a dynamic conducting concept, that is, the resistance of the membrane can be reduced during the fuel cell operation due to the formation of the conducting hydrogen tungsten bronzes. The novel membranes are characterized by different techniques. The results proved that the resistances of the WO3-containing membranes in single fuel cells measured by in situ AC impedance spectroscopy during the operation are significantly lower than that of the single fuel cell using Nafion (R) 112 membrane. It is revealed that the performances of the single fuel cells with WO3/PFSA membranes are superior to that of the single cell with Nafion (R) 112 membrane. (c) 2007 Elsevier B.V. All rights reserved.