In this study, as a proton-conducting material for polymer electrolyte fuel cell applications, the properties of an organic-inorganic electrolyte comprising zirconium sulfophenylphosphonate (ZrSPP) and sulfonated poly(arylene ether sulfone) (SPES) are investigated by changing the ZrSPP/SPES ratio. An increase in this ratio enhances proton conductivity and shifts the O-S-O wavenumber to a high value.