PURPOSE: To provide the titled compsn. which gives moldings having good surface gloss at a low mold temperature, consisting of polyethylene terephthalate, a nucleating agent and a specified amide ester.

CONSTITUTION: 0.05W10pts.wt. at least one nucleating agent selected from polyamides which have two or more amide bonds per molecule and are not molten nor decomposed at a temp. below 270°C, metal salts of org. acids of formulasI and II (wherein M, M' are each an alkali metal; m,n is each 1 or 2) and talc, and 0.5W10pts.wt. amide ester of formula III (wherein R1, R3 are each a 6W 15C hydrocarbon group; R2 is 7C or lower hydrocarbon group) are blended with 100pts.wt. polyethylene terephthalate having an intrinsic viscosity of 0.4 or above.

EFFECT: The compsn. does not contain any components which volatilize during melt kneading or during molding, exhibit excellent moldability even at a low mold temp. of nearly 100°C, and gives moldings having excellent surface gloss and shape retention.