TECHNOLOGY FOCUS - POLYMERS - Preparation (Claimed): Preparation of the proton conductive electrolyte comprises: adding a base to (2) to obtain a corresponding salt; adding (1) and a solvent to the corresponding salt to prepare a mixture; and polymerizing the mixture. Preferred Process: The preparation further comprises impregnating the polymerization product with an acid (a phosphoric acid at 150-500 parts by weight based on 100 parts by weight of (1)). The polymerization is performed at 80-120degreesC, and is performed under irradiation from an electron beam, a gamma beam, a neutron beam, a microwave, a laser beam, an infrared beam and/or an ultraviolet beam. The polymerizing is performed by casting the mixture and drying the cast result at 80-120degreesC. Preferred Components: The mixture of (1) and (2) further comprises a cross linking agent (5-30 parts by weight based on 100 parts by weight of (1)). The cross linking agent is an aziridine based compound and/or an oxazoline based compound. The aziridine based compound is a modified diisocyanate or a diepoxide compound. The polyethylene(metha)acrylic acid is 30-65 parts by weight based on 100 parts by weight of (1). The proton conductive electrolyte further comprises an acid such as a phosphoric acid (150-500 parts by weight based on 100 parts by weight of (1)). The base comprises at least one compound such as ammonia water, triethylamine, tributylamine, sodium hydroxide, potassium hydroxide or lithium hydroxide. EXAMPLE - Ammonia water (100%) was added to polyethylene(metha)acrylic acid (40 parts by weight). The resultant mixture was blended with a water-born polyurethane (30 parts by weight), an aziridine based compound (10 parts by weight), and Epocros (RTM: An oxazoline based compound) (20 parts by weight) and an oxazoline based compound. A deionized water, as a solvent, was added to the result of the blending and then mixed. The mixture was cast and dried at 120degreesC for 4 hours to form a membrane of about 100 microns thickness. The membrane was impregnated with 85% phosphoric acid at room temperature for 2 hours to produce a proton conductive electrolyte.