Silicon nitride films were synthesized by ion-beam-enhanced-deposition (IBED) on an IBED system. Auger electron spectroscopy, X-ray diffraction (XRD), X-ray photoemission spectroscopy (XPS) and the scratch test were performed for investigating the composition, structure and the adhesion with the substrate of them. It was found that the silicon nitride film is composed of a thin silicon enriched top layer, a stoichiometric Si 3 N 4 layer and a mixing layer at the film-substrate interface. Cyclic oxidation tests were carried out on the TiAl coated with the silicon nitride films of thicknesses of 0.5, 1 and 2 μm. The results revealed that IBED silicon nitride film is effective to improve the oxidation resistance of TiAl at high temperature. The 0.5 μm silicon nitride film demonstrated an excellent oxidation resistance at 1300 K for at least 30 cycle (600 h).