Novel ion–exchange membrane has been developed using polyolefin reinforcement as the alternative to ordinal polyvinylchloride (PVC) material. New membrane has almost the same practical properties as the ordinal PVC membranes and shows quite a low water permeability, which indicate smallest occurrence of undesirable water path even with polyolefin reinforcement. Due to the higher stability of polyolefin, new membrane shows better stability in its strength and permselectivity than ordinal PVC membrane in NaOH aqueous solution at 60 ℃. In electrodialysis evaluation, new membrane pair and ordinal PVC membrane pair shows quite a similar performances. New membrane has been launched and is enlarging applicable field gradually.