The present invention relates to a thermoplastic resin composition, a method of preparing the same, and a molded article manufactured using the same. More particularly, the present invention relates to a thermoplastic resin composition including an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A) including a seed obtained by polymerizing 35 to 58 % by weight of an alkyl acrylate and 42 to 65 % by weight of an aromatic vinyl compound, a rubber core formed to surround the seed and obtained by polymerizing 78 to 91 % by weight of an alkyl acrylate and 9 to 22 % by weight of an aromatic vinyl compound, and a graft shell formed to surround the rubber core and obtained by polymerizing 65 to 82 % by weight of an aromatic vinyl compound, 12 to 30 % by weight of a vinyl cyanide compound, and 3 to 15 % by weight of an alkyl acrylate; and a non-graft copolymer (B) including an alkyl (meth)acrylate, an alkyl-substituted styrene-based compound, and a vinyl cyanide compound, wherein the average particle diameter and refractive index of each layer of the graft copolymer (A) are properly adjusted, a method of preparing the thermoplastic resin composition, and a molded article manufactured using the thermoplastic resin composition.
According to the present invention, the present invention has an effect of providing a thermoplastic resin composition having excellent transparency, gloss, blackness, weather resistance, heat resistance, and impact resistance, a method of preparing the same, and a molded article manufactured using the same.