Nanostructured　W-Cu-Cr　composites　were　fabricated,　which　exhibit　exceptionally　high　hardness　(similar　to　1000　HV)　as　compared　with　those　of　the　conventional　W-Cu　composites,　due　to　the　combined　advantages　of　Cr　dissolution,　precipitate　formation　and　grain　refinement.　Nonmonotonic　variation　of　the　wear　resistance　with　hardness　was　discovered.　With　an　appropriate　content　of　Cr,　the　preferential　oxidation　reduced　the　oxidation　of　W.　Moreover,　it　facilitated　formation　of　a　stable　protective　film　with　fish-scale　morphology　and　also　refined　the　structure,　leading　to　a　high　microhardness　at　the　worn　surface.　The　wear　rate　(1.65　x　10(-6)　mm(3)　N-1　m(-1))　was　reduced　by　an　order　of　magnitude　compared　with　that　of　the　conventional　counterpart.　However,　excessive　addition　of　Cr　may　deteriorate　the　wear　resistance　in　spite　of　a　higher　hardness　due　to　the　embrittlening　of　W　phase　and　difficulty　to　form　a　stable　protective　film　at　the　worn　surface.　This　study　provides　a　new　strategy　for　developing　W-Cu　composites　with　outstanding　wear　resistance.