The instant disclosure provides a method for manufacturing an electroless plating substrate and a method for forming a metal layer on a surface of a substrate. The method for preparing the electroless plating substrate includes: providing a substrate; attaching a self-adsorbed catalyst composition to a surface of the substrate; and performing an electroless metal deposition for forming an electroless metal layer on the surface of the substrate. The self-adsorbed catalyst composition includes a colloidal nanoparticle and a silane compound. The colloidal nanoparticle includes a palladium nanoparticle and a capping agent enclosing the palladium nanoparticle. The silane compound has at least one amino group to interact with the colloidal nanoparticle. A covalent bond between the silane compound and the surface of the substrate is formed through the at least one silane group of the silane compound. The colloid nanoparticle has a particle size ranging from 5 to 10 nanometers.