We use the first-principles molecular-dynamics¡@simulation method (MD), which is based on the density functional theory (DFT) with local-density approximation (LDA), to calculate the sticking property of a carbon atom on hydrogen covered C(100) surface. We focused on trajectories and kinetic energy transfer of the gas-phase C atom for four incident angles of =0, £k/8, £k/6 and £k/4. We find that the calculated trajectories and the kinetic energy transfer of the gas-phase atom, Cn, overall are not very sensitive to the change of the incident angle. The insensitivity of the sticking property on the incident angle may be due to a large chemisorption energy, which bends the trajectory of Cn toward the surface, so that Cn is confined to move within a small range.