A　novel　surface　modification　technique　was　successfully　developed　to　significant　ly　enhance　the　hydrophobicity　of　copper.　In　the　technique,　the　carefully-cleaned　copper　disk　was　first　immersed　in　a　mixed　solution　of　2　mol/L　KOH　and　0.1　mol/L　K2S2O4　for　15　min.　at　60°C,　and　then,　it　was　oxidized　in　a　pressure　of　1　Pa　at　an　evaluated　temperature　for　1~5　h.　The　microstructures　and　hydrophobicity　of　the　copper　surface,　before　and　after　surface　modification,　were　characterized　with　X-ray　diffr　action,　energy　dispersive　spectroscopy,　scanning　electron　microscopy　and　contact　a　ngle　measurement.　The　results　show　that　the　surface　modification　results　in　forma　tion　of　a　bi-layer:　a　pedal-shaped　micrograins　of　copper　hydroxide　layer　on　top　of　the　laminar-shaped　nano-grains　of　copper　oxide　and/or　residue　copper-hydr　oxide,　and　that　the　composite　layer　results　in　a　super-hydrophobic　surface,　with　a　contact　angle　up　to　150°,　and　a　sliding　angle　less　than　10°.　The　possible　mech　anism　was　tentatively　discussed.