The　pitting　behavior　of　high　nitrogen　austenitic　stainless　steel　316LN　was　studied　by　using　the　modified　potentiostatic　pulse　test　(PPT).　The　results　show　that　the　duration　of　the　high　potential　(Eh)　and　the　low　potential　(El)　significantly　affect　the　pitting　size　and　number　of　316LN.　However,　the　pitting　behavior　of　316LN　only　changes　during　the　first　five　pulse　cycles,　because　the　metastable　pitting　initiates　at　the　limited　inclusions.　The　optimal　PPT　condition　is　regarded　as　Eh　=　0.5　VSCE　for　1　s,　E1　=　0.2　VSCE　for　2　s　and　ten　pulse　cycles.　Metastable　pits　initiate　at　the　susceptible　sites　of　inclusions　which　are　identified　as　SiO2　and　SiC.　The　metastable　pits　will　further　grow　or　restrain　with　the　increasing　time　of　Eh　or　El,　respectively.　After　PPT　modification,　the　pitting　resistance　of　316LN　is　enhanced　due　to　the　removal　of　the　Si-enriched　inclusions　from　the　316LN　surface.　Meanwhile,　the　fewer　current　transitions,　the　lower　passivation　current　density　and　the　higher　impedance　all　suggest　that　the　protectiveness　of　the　oxidation　film　formed　on　316LN　surface　is　improved　after　PPT.　©　2022