Zr-Si-N films were prepared by radio frequency powered reactive magnetron sputtering at different N2 partial pressures. The influences of N2 partial pressure on the microstructure and properties of Zr-Si-N films were studied. The results reveal that the Zr/Si ratio decreases and the sheet resistance increases as the N2 partial pressure increases. The microstructures of Zr-Si-N films are composed of nano-crystallite ZrN embedded into amorphous matrix of SiNx phase and a small quantity of Zr2Si produced at low N2 partial pressure. The appearance of Zr2Si phase is related to the low nitridation level. The microhardness of Zr-Si-N film decreases with the increase of N2 partial pressure at the N2 partial pressure of 0.03 Pa, the microhardness of Zr-Si-N films is possessed of maximum value of about 22.5 GPa. The phenomenon that high N2 partial pressure results in low microhardness in Zr-Si-N films may be related to the lattice distortion induced by the addition of Si.