Diamond-like carbon (DLC) films, prepared by RF plasma CVD, were implanted at a dose of 5×1015Ar/cm2 with various ion energy of 50, 100, 140, 180 keV. Before and after ion implantation, IR absorption spectra, Raman spectra, optical gap Eopt, hydrogen contents and resistivities were measured. The results show that C-H bonds are destroyed and sp2 and sp3 components are decreased during implantation. While the ratio of (sp2/sp3) increases with ion energy. The Eopt, resistivities and hydrogen contents decrease with ion energy increasing. Ho-wever, at 180 keV, the above parameters have no evident change. These results are also discussed in this paper.