Abstract: Oxidized copper powder was coated with an antioxidant which was self-made in the laboratory.The mechanism of the oxides removal from and the coating of the ultrafine oxidized copper power were investigated.IR,XRD and XPS analyses results showed that after pickled with 5% H₂SO₄ and dipped in 0.1%~0.5% anti-oxidant solution at 60℃ for a proper period of time,the surface of the powder was covered with a protective anti-oxidant film which will prevent the surface from environment attach,but don't affect the conductivity of the powder and the film is stable under 50℃ in 5% H₂SO₄,5%NaOH and 5% NaCl solutions.