A method of producing metal nanoparticles in a high yield rate and uniform shape and size, which is thus suitable for mass production. In addition, metal nanoparticles are provided that have superior dispersion stability when re-dispersed in various organic solvents, which thus suitable for use as a conductive ink having high conductivity. The method of producing nanoparticles includes mixing a metal precursor with a copper compound to a hydrocarbon based solvent, mixing an amine-based compound to the mixed solution of the metal precursor with copper compound and hydrocarbon based solvent, and mixing a compound including one or more atoms having at least one lone pair, selected from a group consisting of nitrogen, oxygen, sulfur and phosphorous to the mixed solution of the amine-based compound, metal precursor with a copper compound and hydrocarbon based solvent.