Commercial Cu0.62Zn0.38foil was subjected to surface mechanical attrition treatment (SMAT) processing. The original and SMAT Cu0.62Zn0.38 foils are thermally oxidized at 500°C under N2-5%O2 gas environments, at a pressure of 1 atm for 3 hours. The oxidized specimens were characterized with a scanning electron microscope, an X-ray diffractometer. It is found that nanosheets are easily formed on the SMAT specimen surface. The favorable formation of nanosheets relates to twin–matrix lamellae structure.