Silver-bearing　antibacterial　duplex　stainless　steels　were　prepared　by　adding　silver　granules　(code　name　A)　or　150~300　μm　Cu-Ag　particles　(code　name　B)　respectively.　The　two　steels　were　then　subjected　to　solid　solution　treatment　at　1150　℃.　The　surface　passive　films　formed　on　the　two　steels　after　potentiodynamic　polarization　test　in　bacteria　bearing　liquid　were　analyzed　by　X-ray　photoelectron　spectroscopy　(XPS).　The　results　indicated　that　there　exist　silver　as　atomic　Ag　and　oxide　AgO,　while　chromium　as　CrO2,　CrO3　and　Cr(OH)3　in　the　surface　passive　film　of　the　steel　A.　However　silver　as　oxides　of　AgO,　Ag2O　and　Ag3O,　while　Cr　as　chromic　oxides　of　multi-valence　present　in　the　surface　passive　film　of　the　steel　B.　In　comparison　with　the　passive　film　on　the　steel　A,　that　on　the　steel　B　has　higher　amount　of　Cr2O3,　molybdenum　oxides　and　MoO4　2-,　but　lower　amount　of　hydroxides/hydrates,　meaning　that　the　stability　of　the　passive　film　on　the　steel　B　is　better.　©　2018,　Chinese　Society　of　Corrosion　and　Protection.　All　rights　reserved.