Abstract: In order to provide a novel thermoplastic resin composition capable of exhibiting high impact resistance using an impact modifier having good dispersibility and can be isolated as a resin powder without coarsening and agglomeration, and a process for preparing the same, the invention provides a thermoplastic resin composition comprising a thermoplastic resin (a) and 0.5 to 20 parts by weight of a graft copolymer (b) comprising a butadiene-based rubbery polymer and a hard shell based on 100 parts by weight of the thermoplastic resin (a), wherein the composition further comprises 0.01 to 3.0 parts by weight of an aqueous polymer compound (c) having a property to form a physical gel, and 0.01 to 10 parts by weight of a processing aid (d), per 100 parts by weight of the graft copolymer (b), and a process for preparing the thermoplastic resin.