A method of preparing a quantum dot nanoparticle is disclosed. The method includes the step of reacting one or more cation precursors including one or more of Groups 12 and 13 elements with one or more anion precursors including one or more of Group 15 elements to prepare a quantum dot nanoparticle, wherein the reaction of the cation precursors and the anion precursors is carried out while supplying a compound represented by Chemical Formula 1. A quantum dot nanoparticle prepared by the preparation method, a quantum dot nanoparticle having a core-shell structure containing the quantum dot nanoparticle as a core, and a light emitting element comprising the quantum dot nanoparticle having a core-shell structure are also disclosed.