A copper-base bulk metallic glass, Cu60Zr30Ti10 (Cu3), and its crystalline counterpart (XCu3) were oxidized in air at 300-500℃. The oxidation kinetics generally followed the parabolic law, and the oxidation rate constants increased with increasing temperature. It was found that the oxidation resistance of XCu3 is superior to that of Cu3. Based on XRD analyses, the scales formed on the XCu3 were composed of mostly CuO and Cu2O, while minor amounts of cubic-ZrO2 and ZrTiO4 were also detected for the Cu3. XRD peaks detected on the substrate of Cu3, indicating phase transformation was taken place after oxidation at 400℃.