Proton conductive polymer electrolyte and fuel cell including the same

A proton conductive polymer electrolyte includes an acidic functional group-containing aromatic hydrocarbon polymer and an electron donor functional group-containing compound. When used in a fuel cell, the proton conductive polymer electrolyte provides a long-term stable power generating performance at an operating temperature from 100° C. to 200° C. in non-humidified conditions or a relative humidity of 50% or less.