A method for electroless metal deposition and an electroless metal layer included substrate are provided. The method for electroless metal deposition includes steps as follows. a) cleaning a substrate, applying a hydrofluoric acid onto the substrate; and then applying a modifying agent onto the substrate to form a chemical oxide layer on the substrate; b) a catalyst layer is formed on the chemical oxide layer, wherein, the catalyst layer includes a plurality of colloidal nanoparticles, and each of the plurality of colloidal nanoparticles includes a palladium nanoparticle and a polymer which encapsulates the palladium nanoparticle, and c) depositing a metal on the catalyst layer through an electroless metal deposition to form an electroless metal layer.