Proton conducting membranes composed of phosphotungstic acid (PWA) and poly(vinyl alcohol) (PVA) were prepared. Conductivity and Fourier transform infrared spectrometer (FTIR) measurements show that most of the acid embedded are stable in the PVA matrix when the membrane is immerged in water or methanol solution at room temperature. Conductivity of the composite membranes scatters around 10(-3) S.cm(-1) at room temperature. The methanol crossover through the membranes is about an order of magnitude lower than that through Nafion 117 membrane.