The　crossion　behavior　of　cast　SAF2906　super　duplex　stainless　steel　(SDSS)　after　solution,　crygenic　and　aging　treatment　in　artificial　brine　solution　were　studied　by　electrochemical　impendance　spectroscopy　(EIS).　The　results　show　that　the　2906　SDSS　after　different　heat　treatments　have　same　EIS　characteristics,　which　exhibits　a　single　capacitive　loop.　After　solution　treatment　and　cryogenic　treatment,　the　capacitence　of　double　layer　of　sample　decreases　and　the　impedance　modulus　increases.　Aging　treatment　can　lead　to　the　precipitation　of　intermetallic　phases　from　matrix,　which　causes　the　increase　of　the　double　layer　capacitance　and　makes　the　impedance　modulus　of　the　aging　specimen　seven　order　of　magnitude　smaller　than　that　of　solution　treated　specimen.　The　longer　aging　time　is,　the　greater　the　variation　of　the　two　parameters　and　the　poorer　the　corrosion　resistance.