CrN films were deposited on 304 stainless steel by DC reactive magnetron sputtering. The effects of nitrogen flow on the microstructure, mechanical and tribological properties were characterized by X-ray diffraction, scanning electron microscopy, atom force microscope, microhardness, wear tester and Nanomap 500LS profile. The results showed that with the increase of nitrogen flow, the CrN films exhibited a preferential orientation in the (200) direction. The deposition rate of CrN films decrease with the increase of nitrogen flow. Besides, the surface roughness exhibited the tendency of decrease first and then increase with further increase of nitrogen flow. As nitrogen flow increased from 15 to 30 sccm, microhardness was improved from 527.34 HV to 1042.26 HV, and then decrease to 918 HV when the nitrogen flow further increase to 35 sccm. Wear test showed that the CrN films deposited at nitrogen flow of 30 sccm was achieved lowest friction coefficient with 0.93 and wear rate with 2.02×10-15m3·(N·m)-1, which presented best wear resistance performance.