The influence of cathodic arc plasma titanizing on the structure and tribological performance of 316L stainless steels was studied by scanning electron microscope, X-ray diffractometer, micro-hardness tester, 3D profile-meter, and reciprocating tribometer in the paper. It was found that the closely adherent titanized layer with a peak titanium content of 66 wt.% can be obtained by cathodic arc plasma titanizing. The titanized layer is composed of Fe2Ti and NiTi; the surface hardness of the titanized layer with a depth of 150μm is increased to 400 HV from 200 HV of original substrate. Under dry friction, the friction coefficient of the titanized layer is obviously lower than that of the original substrate, and the cathodic arc plasma titanizing improves the wear resistance of 316L stainless steels by 6 times. The wear mechanism of the original substrate is abrasive wear, oxidation wear and adhesive wear, while the wear mechanism of the titanized samples is mass loss caused by flaking of the particles in the titanized layer.