The present invention relates to a thermoplastic resin composition, more precisely, a thermoplastic resin composition with enhanced impact resistance, gloss, weather resistance and scratch resistance, compared with the conventional thermoplastic resin compositions, by containing an acrylate-styrene-acrylonitrile (ASA) graft copolymer, an aromatic vinyl compound and vinyl cyan compound copolymer, an alkyl methacrylate/aromatic vinyl compound/vinyl cyan compound terpolymer and a di-block copolymer (aromatic vinyl compound/vinyl cyan compound--alkyl methacrylate/aromatic vinyl compound/vinyl cyan compound).