The work aims to study corrosion resistance of nitrided layer and SS304 by performing surface ion nitriding to SS304 at different temperature at 300Pa. The corrosion resistance of nitrided layer and SS304 in 3.5% NaCl solution was analyzed by potentiodynamic polarization curve and electrochemical impedance spectroscopy. Morphology and phase composition of the nitrided layer and SS304 were analyzed and tested by ustilizing metalloscope, SEM and XRD. Hardness and cross-section morphology of the two were analyzed and tested by ustilizing microhardness tester and metallographic microscope. γ and M phases were present in SS304, γN, Fe2~3N and Fe4N were present in the nitrided layer sample at 400 . Fe ℃ 2~3N, Fe4N and CrN were present at ＞450 ℃. In the 3.5% NaCl solution, self-corrosion current density of the nitrided layer was lower than that of SS304 at 400 ℃ . At ＞450 ℃, it was also lower than that of SS304 and gradually increased as the nitriding temperature increased. The self-corrosion corrosion potential of the nitrided layer was higher than that of SS304 at 400 ℃. At ＞450 ℃, it was higher than the latter and gradually decreased as the nitriding temperature increased. At 400 ℃, membrane resistance of the nitrided layer was bigger than that of SS304; at ≥450 ℃, that was smaller. Inconclusion, the corrosion resistance of the nitrided layer reduces as the temperature increases. The corrosion resistance of nitrided layer is superior to that of SS304 at 400 ℃ and lower than that of SS304 at ＞450 ℃. Nitrogen expanded austenite (γN) is produced in the nitrided layer at 400 ℃, significantly improving corrosion resistance of the nitrided layer while CrN is produced at ＞450 ℃, reducing the corrosion resistance simultaneously.