Electrospun poly(ether sulfone) (PES) membrane impregnated with Nafion (PES-N) have been developed for high-temperature polymer-electrolyte membrane fuel cell (HT-PEMFC). The PES-N obtains highly thermal stability up to 430 degrees C, which is higher than that of the commercial Nafion 212. The PES-N membrane shows a good proton conductivity of about 10(-2) S cm(-1) in a temperature range from 75 degrees C to 120 degrees C. The membrane-electrode assembly (MEA) with the PES-N membrane exhibits a current density of 1.697 A cm(-2) at 75 degrees C, and 0.813 A cm(-2) at 110 degrees C when the applied voltage is 0.6 V, whereas the MEA with the Nafion 212 membrane shows the current density of 0.647 Acm(-2) at 110 degrees C. The results suggest that the PES-N can be a good candidate for a polymer electrolyte membrane of the HT-PEMFC.