Hydrogen-free SiNx films were deposited by direct current pulse magnetron sputtering at room temperature. We have studied the influence of N2 flow rate and Si target sputtering power on the structural characteristics and properties of deposited films by using Fourier-transform infrared spectroscopy，auto water vapor permeability tester，ultraviolet-visible spectrophotometer，stylus profilometer，and contact angle measurement. The results indicate that the content of Si—O bonding in SiNx films increaseds and moisture resistant property of SiNx films decreases with increasing N2 flow rate or decreasing Si target sputtering power. The films deposited at 300W of Si sputtering power and 6sccm of N2 flow rate show excellent water vapor permeability (0.764) with transmittance higher than 97.5% in visible range.