Single layer graphene prepared by chemical vapor deposition(CVD) was treated by low temperature oxygen plasma. Raman spectrometer and X-ray photoelectron spectroscopy(XPS) were used to characterize the changes before and after the treatment. And then the effects on microstructure were discussed. Significantly enhanced D-band, D′-band and decreased 2D-band were found in the Raman spectra, and right shift occurred to G-band and left shift occurred to 2D-band after the low temperature oxygen plasma treatment. ...