Abstract: Ag-Cu films were deposited at a low temperature (173 K, LT-Ag-Cu films) by arc ion plating. Atomic oxygen (AO) irradiation experiments were conducted using a ground AO simulation facility. The AO resistant and wear behavior of the LT-Ag-Cu films were investigated by X-ray diffraction, atomic force microscope and a ball-on-disk tribometer using Ag film deposited at room temperature (300 K, RT-Ag film) as a reference. The results show that the LT-Ag-Cu films were composed of AgCu alloy and small amount of Ag or Cu. Because of densified microstructure, lower crystallite size and alloying with Cu, the LT-Ag-Cu film represented much better anti-oxidation capability under the AO irradiation condition than that of the RT- and LT-Ag films. Wear results show that as compared with the RT-Ag film, the LT-Ag-Cu films exhibited much better wear resistance due to the better film-substrate adhesion as well as the fine/dense structure, and the wear increase resulted from the AO irradiation was much lower for the LT-Ag-Cu films than the RT- and LT-Ag film due to the improvement in the AO resistant behavior.