CrN films with deposition rates of 30-190 nm/min were deposited on Si (111) substrates by middle-frequency magnetron sputtering methods. XRD, SEM, EDS and microhardness tests were used to investigate the effects of bias voltages and total gas pressure on the structure and mechanical properties of the resulting CrN films. With the increasing of bias voltages and total gas pressure, the preferential diffraction orientation changed from (111) to (200). A smooth surface was observed by the SEM experiments and the thickness of the film was about 2 µm. The deposition rates and Cr content of resulting films were highly influenced by the magnitude of the bias voltage and total gas pressure. RMS and Ra properties of the CrN films increased when increased total gas pressure or decreased bias voltage. CrN films produced under optimal conditions have an almost 1:1 Cr:N ratio as determined by EDS. The hardness of the CrN film increased from 2200 to 2700 HV when increased the bias voltages from 0 to 200 V.