A thermoplastic resin composition of the present invention includes 55 to 70% by weight of a non-grafted copolymer (A) containing 65 to 83% by weight of a (meth)acrylic acid alkyl ester compound, 2 to 12% by weight of an N-substituted maleimide compound, 1 to 6% by weight of a vinyl cyanide compound, and 7 to 17% by weight of an aromatic vinyl compound; 20 to 42% by weight of an acrylate-based rubber-aromatic vinyl compound-vinyl cyanide compound graft copolymer (B) containing acrylate-based rubber having an average particle diameter of 50 to 200 nm; and 1 to 15% by weight of an acrylate-based rubber-aromatic vinyl compound-vinyl cyanide compound graft copolymer (C) containing acrylate-based rubber having an average particle diameter of 300 to 600 nm. Within this range, a thermoplastic resin composition having excellent weather resistance, heat resistance, scratch resistance, and colorability.