Abstract: The subject invention relates to the polyester compositions being composed of (a) an aromatic polyester having the relative viscosity of 1.2 to 2.0, (b) an aromatic polycarbonate having the number average molecular weight of 10,000 to 80,000, and (c) a glycidyl-group containing copolymer consisting essentially of .alpha.-olefine and glycidyl ester of .alpha.,.beta.-ethylenically unsaturated carboxylic acid and having the melt index of 0.1 to 100. They are useful for manufacturing electric, electronic and automotive parts, being superior in flow property and melt stability on molding, as well as in mechanical properties particularly in impact and hot-air aging resistance. The compositions can be molded to form various articles by conventional molding methods.