A new type of ion-exchange nanocomposite membranes was prepared by addition of barium ferrite nanoparticles to a blend containing sulfonated poly (2,6-dimethyl-1,4-phenylene oxide) and sulfonated polyvinylchloride via a simple casting method. Hard magnetic BaFe12O19 nanoparticles were synthesized via a facile sonochemical-assisted reaction. Nanoparticles and nanocomposites were then characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and alternating gradient force magnetometer. Various characterizations revealed that the addition of different amounts of inorganic fillers could affect the membrane performance. The inorganic nanoparticles not only created extra pores and water channels that led to improve ion conductivity, but also provided higher permselectivity and transport number of counter-ions.