A proton exchange membrane based on poly(vinylidene fluoride) filled with nano-sized ceramic fillers and a kind of polymeric acid was prepared and characterized with FT-IR, TGA, and SEM. The membrane shows high and stable conductivity at room temperature. The role of the ceramic filler and the polymer acid in the enhancement of the proton productivity is discussed. Proton conductivities and methanol permeabilities of membranes with different contents of ceramic fillers were investigated. The ratio between the conductivity and methanol permeability shows the membranes with over 16 wt.% content of alumina fillers are the best membranes prepared in this work for use in a direct methanol fuel cell. (c) 2005 Elsevier B.V. All rights reserved.