Zr-Si-N films were deposited on silicon and steel substrates by cathodic vacuum arc with different N-2/SiH4 flow rates. The N-2/SiH4 flow rates were adjusted at the range from 0 to 12 sccm. The films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), hardness and wear tests. The structure and the mechanical properties of Zr-Si-N films were compared to those of ZrN films. The results of XRD and XPS showed that Zr-Si-N films consisted of ZrN crystallites and SiNx amorphous phase. With increasing N-2/SiH4 flow rates, the orientation of Zr-Si-N films became to a mixture of (1 1 1) and (2 0 0). The column width became smaller, and then appeared to vanish with the increase in N-2/SiH4 flow rates. The hardness and Young's modulus of Zr-Si-N films increased with the N-2/SiH4 flow rates, reached a maximum value of 36 GPa and 320 GPa at 9 sccm, and then decreased 32 GPa and 305 GPa at 12 sccm, respectively. A low and stable of friction coefficient was obtained for the Zr-Si-N films. Friction coefficient was about 0.1. (C) 2011 Elsevier B. V. All rights reserved.