The　effects　of　parameters　such　as　circumferential　corrosion　ratio,　axial　corrosion　ratio　and　corrosion　time　on　the　axial　mechanical　behavior　of　slender　circular　steel　tubular　columns　with　localized　corrosion　in　offshore　atmospheric　environment　were　studied.　This　was　conducted　by　using　a　three-factor　and　three-level　orthogonal　test.　A　formula　for　the　axial　compressive　carrying　capacity　of　the　specimens　with　localized　corrosion　was　proposed　according　to　the　test　results.　The　results　indicate　that　the　failure　modes　of　the　specimens　did　not　change,　and　all　failure　modes　were　associated　with　the　extreme　point　instability.　The　stiffness　of　the　specimens　with　similar　corrosion　time　did　not　change　significantly.　However,　the　carrying　capacity　varied　greatly　among　the　localized　corrosion　modes.　The　influence　of　corrosion　time,　circumferential　corrosion　ratio　and　axial　corrosion　ratio　on　the　degradation　of　stiffness　and　carrying　capacity　of　the　specimens　decreased　successively.　The　least　favorable　localized　corrosion　mode　for　the　carrying　capacity　degradation　of　the　specimens　was　H3L3-270,　of　which　the　average　carrying　capacity　degradation　due　to　the　corresponding　factors　were　19.30%,　18.47%　and　22.24%,　respectively.　However,　the　least　favorable　localized　corrosion　mode　for　the　stiffness　degradation　of　the　specimens　was　H1L3-270,　of　which　the　average　stiffness　degradation　due　to　the　corresponding　factors　were　13.53%,　13.38%　and　15.22%,　respectively.　The　carrying　capacities　predicted　by　the　proposed　formula　were　close　to　the　test　results,　and　had　a　certain　safety　margin.　©　2020,　Engineering　Mechanics　Press.　All　right　reserved.