Amorphous carbon films are perspective materials for many biological applications. Laser treatment is very useful technique for precise pattering of diamond-like carbon (DLC) films and the pulsed laser processing has some advantages over mechanical and chemical processing. Additionally, laser influence should depend on the properties of DLC films. The different types of a-C:H films were deposited on Si by direct ion beam using different mixtures of acetylene and hydrogen, liexane and hydrogen. In order to reduce an influence of atmosphere during the laser irradiation, the a-C:H films were coated by silica. After that the samples were irradiated in a scanning mode of a YAG:Nd laser (532nm, 10ns). An increasing intensity of the laser irradiation reduces film thickness, develops a grain structure, increases film density and roughness, and stimulates diffusion of Si atoms into a-C:H film and H atoms into SiOx layer and Si wafer. The films were destroyed at high laser intensities (-10 MW/cm2 or ~7 MW/cm2 for films with high hydrogen (>40at%) concentration). Raman spectra of laser-irradiated samples depend on the initial properties of the a-C:H films. The samples with relatively low H-content (-35%) and high percentage (-70%) of sp3-bonds (DLC films) were not significantly changed using low and moderate laser intensity (Fig.l). At higher intensify -5 MW/cm2, the D-peak decreased and shifted towards lower frequency whereas the G-peak parameters remained almost unchanged. Additionally, infrared spectroscopy indicated an increase CH2 in sp3 hybridization of C-sp3 and C-sp2 modes simultaneously. Contrary, Raman spectra of laser-irradiated (using 4-7 MW/cm2) a-C:H films with initially dominating sp2-bonds (GLC films) were typical for glassy carbon. For the films with high hydrogen (PLC) content, the transformation to glassy-carbon occurs at yet lower laser intensity. Summarizing, the a-C:H films containing higher hydrogen content (PLC films) were more sensitive to laser irradiation. The laser irradiation leads to graphitization of a-C:H films and formation of glassy carbon. As results of laser irradiation, SiC and diamond-like nanocrystals were also formed.