PURPOSE: To obtain a resin compsn. which gives moldings having little failure in appearance without lowering impact resistance, by blending a grafted ethylene/α-olefin copolymer and a piperidine derivative with a thermoplastic polyester.

CONSTITUTION: A graft polymer (A) obtd. by grafting an α, β-unsaturated carboxylic acid or anhydride or a tetrahydrofurfuryl-α, β-unsaturated carboxylic acid onto an ethylene/α-olefin copolymer and a piperidine derivative (B) of formula I or II are blended with a thermoplastic polyester. In formula I, R1WR6 are each H, alkyl ; R7 is hydroxyl, amino, alkoxy, aryloxy, acyloxy, alkoxycarbonyl, etc. In formula II, R1WR6 and R9WR14 are each H, alkyl ; R8 is O, carbonate, aliph., arom. or heterocyclic diacryloxy, dicarbamoyloxy, bisthiocarbamoyloxy, etc.