Abstract: A thin film of palladium over proton exchange membrane Nafion 117 was gained by sputtering palladium or electroless-deposition palladium film methods,respectively.SEM,XRD,EDX,methanol permeability,proton conductivity tests were employed for characterizing the properties of palladium film. SEM topography shows that some cracks are found over sputtered thin palladium film,on the contrary,cracks are hard to found over electroless palladium deposition.EDX spectra analysis implies that the palladium layer is combined with a little phosphorous.XRD pattern indicates that a thin film of poorly crystalline palladium was produced on the membrane successfully.Methanol permeability tests show that palladium deposition over the membranes can reduce the methanol crossover prominently.Thus it is believed that electroless-plating palladium over Nafion117 membrane for reducing methanol crossover in direct methanol fuel cell has potential perspective.