The　corrosion　behaviors　of　stainless　steel　and　nickel-plated　carbon　steel　coupled　with　conductive　polymer　were　investigated　in　both　hot　humid　environment　and　simulated　marine　environment.　The　corrosion　currents　of　different　steel　substrates　and　conductive　polymer　in　simulated　marine　environment　at　room　temperature　were　measured.　The　corrosion　surfaces　of　different　steel　couples　were　observed　under　a　scanning　electron　microscope　(SEM)　and　chemical　compositions　were　examined　by　energy　dispersive　spectrum　(EDS)　analysis.　The　corrosion　mechanism　was　discussed.　The　results　showed　that　the　stability　of　both　stainless　steel　and　nickel-plated　carbon　steel　in　hot　humid　environment　was　excellent　and　no　corrosion　happened　in　the　blank　test　for　360　h　while　slight　corrosion　existed　in　the　contact　area　of　coupled　steel　substrates.　In　simulated　marine　environment,　the　corrosion　current　of　the　stainless　steel　was　lower　than　100　mu　A　and　some　directional　rod-like　particles　formed　on　the　surface　of　the　stainless　steel,　which　are　mainly　caused　by　oxidative　corrosion　among　different　phases.　The　corrosion　current　of　the　nickel-plated　carbon　steel　couples　was　much　greater　than　that　of　stainless　steel　couples　and　nickel　plate　cracking　resulted　in　the　corrosion　of　the　internal　iron　because　the　coated　nickel　layer　was　not　dense　enough.