Microstructure　observation　and　nano-indentation　test　were　carried　out　on　crack　arresting　specimens　of　304　stainless　steel　with　and　without　plastic　zone　near　the　crack　tip.　The　results　show　that　phase　transformation　and　recrystallization　are　found　to　occur　at　the　crack　tip　of　304　stainless　steel　with　plastic　zone　after　pulse　current　arrest,　and　the　solidification　zone,　fine　grain　zone　and　deformation-induced　martensite　zone　are　formed　under　the　co-action　of　the　temperature　field　and　the　stress　field.　However,　the　solidification　zone　is　only　occurred　in　the　specimen　without　the　plastic　zone.　The　nano-indentation　test　shows　that　the　fatigue　crack　tip　of　304　stainless　steel　has　large　residual　stress,　which　decays　rapidly　with　the　increment　of　the　distance　from　the　crack　tip.　After　pulse　current　crack　arrest,　the　formation　of　deformation-induced　martensite　leads　to　the　increase　of　both　the　volume　expansion　and　the　compressive　stress　around　the　arrest　crack,　which　is　beneficial　to　suppress　the　crack　propagation.　©　2020,　Editorial　Office　of　＂Jinshu　Rechuli＂.　All　right　reserved.