Abstract: In the present work, the electric resistance of copper filled composite paint is reduced ten times by addition of coupling agent. And the electric conductivity of the composite paint keeps stable during 500 hours of exposure to air. The mechanism of resisting oxidation is investigated by Flourier Transfer Infrared Spectrometry. It is suggested that the hydrogen bond and the covalence bond between coupling agent and the copper powders are formed. This leads to formation of an oxidation resistant film on the copper powders.