Abstract: A seal molding material for cell electrolytic solution, which comprises an EPDM composition comprising a peroxide-crosslinkable EPDM and an organic peroxide, the seal molding material being for use at the electrode site of a nickel-hydrogen cell, wherein the EPDM composition comprises preferably 100 parts by weight of a peroxide-crosslinkable EPDM, 10 to 150 parts by weight of a filler and 1 to 8 parts by weight of an organic peroxide, and not more than 40 parts by weight of hydrocarbon-based oil can be further contained. The seal material molded from the seal molding material for cell electrolytic solution has a sufficient durability against a potassium hydroxide-based electrolytic solution and a longer life, and is free from any deterioration, when energized at the electrode site of a nickel-hydrogen cell.