To provide a thermoplastic resin composition having impact resistance, rigidity, heat resistance, and fluidity in an excellently-balanced manner, further having excellent dimensional stability, coating properties, and solvent welding properties, and useful as an automotive interior and exterior material and a housing/part-associated material of electric/electronic equipment.

This thermoplastic resin composition comprises a styrene-based resin, a polyamide resin, and a polyolefin-based resin, wherein the polyolefin-based resin is contained in an amount of 0.1-60 wt% and further 0.01-80 wt% of a modified vinyl-based copolymer which contains units of a vinyl-based monomer selected from a group consisting of an α,β-unsaturated carboxylic anhydride and a derivative thereof is added to the composition.