Poly(vinylidene fluoride) grafted polystyrene sulfonated acid (PVDF-g-PSSA) membranes doped with different amount of Al2O3 (PVDF/Al2O3-g-PSSA) were prepared based on the solution-grafting technique. The microstructure of the membranes was characterized by IR-spectra and scanning electron microscope (SEM). The thermal stability was measured by thermal gravity analysis (TGA). The degree of grafting, water-uptake, proton conductivity and methanol permeability were measured. The results show that the PVDF-g-PSSA membrane doped with 10% Al2O3 has a lower methanol permeability of 6.6 x 10(-8) cm(2) s(-1), which is almost one-fortieth of that of Nafion-117, and this membrane has moderate proton conductivity of 4.5 x 10(-2) S cm(-1). Tests on cells show that a DMFC with the PVDF/10%Al2O3-g-PSSA has a better performance than Nafion-117. Although Al2O3 has some influence on the stability of the membrane, it can still be used in direct methanol fuel cells in the moderate temperature. (c) 2006 Elsevier B.V. All rights reserved.