Disclosed herein is a method for forming quantum dots, comprising the steps of (a) depositing a metal thin layer onto a substrate, (b) coating a dielectric precursor onto the metal thin layer, and (c) stepwisely heating the resultant substrate; or a method for forming quantum dots, comprising the steps of (a) mixing a dielectric precursor diluted in a solvent and a metal powder and stirring the mixture, (b) coating the mixture onto a substrate, and (c) heating the resultant substrate. The method can easily control the size, density and uniformity of metal oxide quantum dots.