The invention relates to a resin composition for a battery case for secondary battery, comprising: (a) about 100 parts by weight of a polypropylene type resin having a density of propylene polymer portion of about 0.905 g/cm.sup.3 or more and an MFR of about 0.1 to 12, composing a matrix phase, (b) about 0.5 to 10 parts by weight of component (b-1) or (b-2), composing a dispersed phase polymer, and (c) a hydrogenated block copolymer obtained by hydrogenating a block copolymer; said hydrogenated block copolymer composing a boundary surface between the component a) and the component (b); wherein (b-1) is a hydrogenated block copolymer having a number average molecular weight of about 100,000 or more, in terms of polystyrene, and (b-2) is a high-density polyethylene having a density of about 0.940 g/cm.sup.3 or more.