To explore the friction and wear properties of TiN coating under oil lubrication,TiN coatings were deposited on AISI304 stainless steel by magnetron sputtering technology.The effect of nitrogen flux ratio on the microstructure and mechanical properties of TiN coatings,as well as their tribological performance under lubrication of rapeseed oil were studied by using SEM,nano-scratch meter,XRD,XPS and tribotester.The experimental results show that the TiN coating deposited at the nitrogen flux ratio of 0.45 has denser crystal structure and better mechanical properties.The friction coefficient and wear rate of TiN coatings decrease firstly and then increase with the increase of nitrogen flux ratio,and both of them are minimum when the nitrogen flux ratio is 0.45 under lubrication of rapeseed oil.XPS analysis of the wear scar shows that the existence of oxidation layer on the surface of TiN coating increases the wettability of rapeseed oil on the surface of the coating,leading to good lubricating properties.Compared with olive oil,polyalphaolefin (PAO6) base oil and 5W40 oil,TiN coating exhibits better lubrication performance when lubricated by rapeseed oil.