The fabrication of a-C:H films from methane has been performed using dielectric-barrier discharges at atmospheric pressure. The effect of combined-feed gas, such as carbon dioxide,carbon monoxide or acetylene on the formation of a-C:H films has been investigated. It hasbeen demonstrated that the addition of carbon monoxide or acetylene into methane leads to aremarkable improvement in the fabrication of a-C:H films. The characterization of carbon filmobtained has been conducted using FT-IR, Raman and SEM.