Objective To improve the corrosion resistance of 304 stainless steel. Methods TiN coating was fabricated on the surface of 304 stainless steel by magnetron sputtering. The microstructure distribution and chemical composition of TiN coating were characterized by SEM, XRD and GDOES. The corrosion behavior of 304 stainless steel and TiN coatings in 3. 5 wt. % NaCl solution (pH=2. 5) was discussed by polarization curves and electrochemical noise technique. The failure mechanisms of coating was studied according to the electrochemical noise signals, the noise resistance and corrosion morphology. Results The smooth and dense TiN coating with a thickness of about 1 μm was deposited on 304 stainless steel. Substrate and TiN coating showed passivation and pitting in polarization curves, and the values of corrosion potential (Ecorr) and corrosion current density (Jcorr) of substrate were -0. 41 V and 8. 01×10 -6 A / cm2 , respectively. However, for TiN coating the value of Ecorr( -0. 28 V)shifted toward the positive, and the value of Jcorr(6. 34×10 -8 A / cm2 ) decreased sharply. All the results showed the TiN coating exhibited an excellent corrosion resistance. The results of electrochemical noise showed that the TiN coating revealed fewer transients, higher amplitude current transients and lower noise resistance (Rn) at beginning of the testing. However, with increasing immersion time the current transients of TiN coating showed a significant change, and the value of Rn had a sharp increase, compared with the substrate. The corrosion micrograph showed that the pitting occurred on the substrate and TiN coating. Conclusion TiN coating could obviously improve the corrosion resistance of 304 stainless steel. TiN coating acted as the physical barrier, and the corrosion resistance was mainly limited by the pinhole and break.