A　robust　method　for　epitaxial　deposition　of　Au　onto　the　surface　of　Ag　nanostructures　is　demonstrated,　which　allows　effective　conversion　of　Ag　nanostructures　of　various　morphologies　into　Ag@Au　counterparts,　with　the　anisotropic　ones　showing　excellent　plasmonic　properties　comparable　to　the　original　Ag　nanostructures　while　significantly　enhanced　stability.　Sulfite　plays　a　determining　role　in　the　success　of　this　epitaxial　deposition　as　it　strongly　complexes　with　gold　cations　to　completely　prevent　galvanic　replacement　while　it　also　remains　benign　to　the　Ag　surface　to　avoid　any　ligand-assisted　oxidative　etching.　By　using　Ag　nanoplates　as　an　example,　it　is　shown　that　the　corresponding　Ag@Au　nanoplates　possess　remarkable　plasmonic　properties　that　are　virtually　Ag-like,　in　clear　contrast　to　Ag@Au　nanospheres　that　exhibit　much　lower　plasmonic　activities　than　their　Ag　counterparts.　As　a　result,　they　display　high　durability　and　activities　in　surface-enhanced　Raman　scattering　applications.　This　strategy　may　represent　a　general　platform　for　depositing　a　noble　metal　on　less　stable　metal　nanostructures,　thus　opening　up　new　opportunities　in　rational　design　of　functional　metal　nanomaterials　for　a　broad　range　of　applications.