The nitrogen interstitials solution in Fe-Cr-Ni austenitic stainless steel has been formed by a series of plasma/ion nitrogen-modified processes at a low process temperature of 350-450℃.A high nitrogen face-centered-cubic phase (n-) layer on the austenitic stainless steel has a 10-20 m thickness with a peak nitrogen content of about 20-35 at.%.A high microhardness on the austenitic stainless steel was obtained up to 20-22 GPa.The superior wear and corrosion resistance of the n-phase layer on the austenitic stainless steel were investigated by tribological test on a ball-on-disc tribometer and by electrochemical test using a standard three electrodes system in NaCl solution, respectively.The oxidative wear mechanism of the n-phase on the austenitic stainless steel was found through the nitrogen-enhanced dissolution instead of an adhesive wear mechanism of the original austenitic stainless steel.With the higher applied load, a transition of the wear mechanisms from oxidative to abrasive wear was carried out, due to a hexagonal-close-packed martensite phase transformation of the n-phase during the wear tests.The nitrogen interstitials in the n-phase layer contributed to inhibiting the adsorption of aggressive chloride ions in the outer n-type iron hydroxide/oxides region, to restricting the migration of space charges as a complete barrier from the n-type and p-type semiconductors regions, and to neutralizing of the protons due to the formation of ammonia in NaCl solution on the pitting corrosion resistance.The wear and corrosion resistance mechanism of the n-phase has been explored based on the composition, microstructure, and wear and corrosion properties of the plasma/ion nitrogen-modified austenitic stainless steel.