The diamond-like carbon (DLC) films were deposited by KrF excimer laser (λ=248 nm) ablation under H 2 atmosphere of 200 mtorr with 6 J/cm 2 . The prepared DLC thin film was mounted on the holder and the film surface was irradiated with the third harmonic of a single pulsed of Nd:YAG laser (λ=355 nm) or a pulsed KrF excimer laser. The experiments were performed in air and the substrate was held at room temperature. The threshold energy density for surface damage is measured by inspecting the surface after a single laser shot of increasing fluence to observe the onset of surface damage. The damage threshold energy density for DLC film flashed by a pulsed Nd:YAG laser is in the range 60-80 mJ/cm 2 . The dynamics of pulsed nanosecond laser heating process is simulated by the solution of the one-dimensional heat conduction equation. The finite element method (FEM) is applied to solve the equation. At the laser fluence of 80 mJ/cm 2 with the Nd:YAG laser, the surface reaches the maximum temperature of 785 o C at 48 ns. The experimental and calculated results show that the damage temperature of DLC film is smaller than the vaporization temperature of solid carbon. Moreover, the transmission spectra of DLC films before and after irradiation were measured. The graphitization occurred on the sample after irradiation over threshold energy for surface damage.