To provide a thermoplastic resin composition having excellent transparency with reflex index and compatibility adjusted to each other by regulating the constitution and blending ratio for each resin for use, and excellent balance of heat resistance, impact resistance and moldability.

This thermoplastic resin composition comprises (A) a rubber- modified thermoplastic resin, (B) a heat-resistant thermoplastic resin comprising 98-50 wt.% of a methacrylic ester monomer unit, 1-20 wt.% of an aryl maleimide monomer unit, 1-30 wt.% of an alkyl maleimide monomer unit and 0-15 wt.% of a copolymerizable monomer unit, and having a Vicat softening point of ≥120°C, and (C) another thermoplastic resin that is to be added optionally, wherein the matrix part of (A) is thermodynamically compatible with the mixture of (B) and (C). The composition is excellent in appearance and heat resistance.