Abstract: Disclosed is a production method of a thermoplastic resin composition comprising: blending a thermoplastic resin (A) and a metal complex (B) and a ligand (C2), wherein the metal complex (B) has a ligand (C1) coordinated therein, and wherein the ligand (C2) has a higher boiling point than the ligand (C1) under atmospheric pressure, and then heating and mixing the resulting blend at a temperature of not less than a boiling point of the ligand (C1) and not more than a boiling point of the ligand (C2), to produce a thermoplastic resin composition that can provide a light-emitting body at low cost in which a light-emitting material is dispersed in the resin in a good dispersion state, excellent in transparency and excellent in light-emitting properties of visible light; a molding material obtained by molding the thermoplastic resin composition; and a light-emitting body obtained by molding the thermoplastic resin composition.