PURPOSE: To obtain the title composition excelling in dimensional stability, moldability and heat resistance and improved in impact resistance, by mixing an aromatic polyester resin with a polyphenylene ether resin with a specified multiphase structure thermoplastic resin as a compatibilizer.

CONSTITUTION: The title composition comprising 99W1wt.% aromatic polyester resin (A) (e.g., polybutylene terephthalate), 1W99wt.% polyphenylene ether resin (B) (e.g., poly-2,6-dimethyl-1,4-phenylene ether), 0.1W100pts.wt., per 100pts.wt. total of components A and B, multiphase structure thermoplastic resin (C) comprising 5W95wt.% epoxy olefin copolymer and 95W5wt.% vinyl (co)polymer and in which either of the (co)polymers forms a dispersed phase of a particle diameter of 0.001W10μ, and 0W150pts.wt., per 100pts.wt. total of components AWC, inorganic filler. This thermoplastic resin composition possesses heat resistance inherent in resin B, retains dimensional stability, moldability, etc. inherent in resin A, and is improved in impact resistance by the addition of resin C, and it can be used for industrial parts, etc., requiring heat resistance, such as automobile parts and electrical and electronic components.