TiAlN/TiN, TiAlCN/TiAlN/TiN and TiAlON/TiAlN/TiN multilayer films were prepared on steel substrates by pulsed d.c. plasma-enhanced chemical vapor deposition (PECVD) at 823 K using gas mixtures of TiCl4, AlCl3, H-2, N-2, CH4, O-2 and Ar. We studied the structural, compositional, mechanical and chemical properties of these films. Fracture cross-sections of the TiAlN and TiAlCN films showed columnar structure. On the other hand, those of the TiAlON films showed amorphous-like dense structure. X-Ray diffraction (XRD) analyses showed that the TiAlN, TiAlCN and TiAlON films had NaCl structure. The XRD peaks of the TiAlON films were broad. Glow discharge optical emission spectroscopy (GDOS) analyses proved that these films had multilayer structure. The Vickers hardness of the TiAlN/TiN, TiAlCN/TiAlN/TiN and TiAlON/TiAlN/TiN multilayer films were 2608, 2815 and 1444 Hv, respectively. These multilayer films had higher oxidation resistance and better tribological properties than the TiN single-layer films. The TiAlCN/TiAlN/TiN multilayer films showed the best wear resistance. Furthermore, these multilayer mms demonstrated superior corrosion resistance in a molten aluminum alloy at 953 K. The TiAlON/TiAlN/TiN multilayer films indicated the best corrosion resistance.