Suffonated polyetheretherketone(SPEEK)with various degree of sulfonation(DS)was prepared by sulfonation of commercial VictrexR PEEK．The DS was determined using 1H-NMR method．A series of composite membranes based on SPEEK and phosphotungstic acid(PWA)were prepared by solution casting method．The effects of the DS and PWA content on water uptake

swelling ratio

proton conductivity and methanol permeability of the composite membranes were investigated．The proton conductivifies of the composite membranes inereased with the DS and the PWA content and reacbed a highest value of 1．36×10-2S／cm(20℃)

which was higher that that of the NafionR117 membrane(1．0×10-2S／cm)measured under the same condition．Nearly one order magnitude difference between conductivities measured in transverse and longitudinal directions was found．Thorugh the methanol permeability increased upon the addition of PWA．the methanol permeability of the composite membranes was all lower than that of the Nafion R 117 membrane．