Surface　engineering　has　been　found　to　be　effective　in　promoting　the　catalytic　activities　of　noble-metal-based　nanocatalysts.　In　this　contribution,　by　using　the　PtCuxNi　ternary　alloy　nanocrystal　(NC)　as　the　model　catalyst,　a　surface　tungsten(W)-doping　strategy,　combining　a　surface　oxidative　acid　treatment　protocol,　can　effectively　boost　the　electrocatalytic　activities　of　the　NCs　in　oxygen　reduction　reaction.　The　W-doped　PtCuxNi　alloy　catalysts　show　obvious　enhancement　in　electrochemical　surface　area　and　mass　activity　and　slightly　enhanced　specific　activity　compared　with　the　undoped　catalyst.　Based　on　the　experimental　evidence,　it　is　proposed　that　the　W　doping　involves　a　surface　reconstruction　by　first　removing　the　surface　Pt　atoms　from　the　NC　and　then　reducing　them　back　to　the　surface.　The　existence　of　surface　Ni　atoms　may　be　crucial　in　promoting　the　catalytic　activities　possibly　through　their　electronic　interactions　to　the　active　sites.　The　durability　of　the　W-doped　PtCuxNi　catalysts　is　also　enhanced　possibly　due　to　the　pinning　effect　of　surface　W　atoms.　Therefore,　the　surface　engineering　of　PtCuxNi　ternary　alloy　by　W　atoms　can　effectively　modulate　its　activity　and　durability.