The　effect　of　sodium　butyl　xanthate　(NaBX)　and　dodecylamine　(DDA)　as　combined　collector　on　the　sulphidizing　flotation　of　copper　oxide　was　investigated　by　flotation　test,　fluorescent　pyrene　probe,　zeta　potential,　and　infrared　spectroscopy　analyses.　The　micro-flotation　results　show　that　combined　use　of　NaBX+DDA　yields　better　effect　than　using　NaBX　at　pH　7-11　only,　and　the　optimal　molar　ratio　of　NaBX　to　DDA　is　2:　1.　The　actual　ores　flotation　shows　that　when　the　dosage　of　NaBX+DDA　is　(100+54)　g/t,　the　copper　concentrate　grade　and　recovery　are　15.93%　and　76.73%,　respectively.　The　fluorescent　pyrene　probe　test　demonstrates　that　the　NaBX+DDA　can　reduce　the　micelle　concentration　in　the　pulp.　The　zeta　potential　and　the　infrared　spectroscopy　analyses　indicate　that　chemical　adsorption,　hydrogen-bonding　and　electrostatic　interaction　can　help　to　adsorb　NaBX+DDA　on　the　surface　of　malachite.　Meantime,　copper　xanthate　and　copper-amine　complexes　may　be　generated　during　the　adsorption　process.