The　seismic　behavior　of　a　circular　concrete-filled　steel　tubular　(CFST)　subjected　to　localized　corrosion　was　investigated　experimentally.　The　effects　of　localized　corrosion　parameters　(corrosion　depth　ratio,　circumferential　corrosion　ratio,　longitudinal　corrosion　ratio,　and　longitudinal　location　of　the　corrosion)　on　the　seismic　behavior　were　analyzed.　The　experimental　results　showed　that　localized　corrosion　significantly　influenced　the　failure　mode　of　the　CFST　columns.　The　hysteresis　curves　exhibited　a　pinching　phenomenon　and　were　asymmetrical　about　the　coordinate　origin　for　the　specimens　under　one-sided　corrosion　at　the　bottom　of　the　column.　The　seismic　performance　deteriorated　with　increasing　corrosion　depth　ratio,　circumferential　corrosion　ratio,　and　longitudinal　corrosion　ratio　for　CFST　columns　corroded　at　the　bottom.　Corrosion　at　the　mid-height　of　the　CFST　columns　had　less　adverse　effects　on　seismic　performance　than　corrosion　at　the　bottom.　Moreover,　the　plastic　hinge　varied　with　the　corrosion　depth　ratio　and　circumferential　corrosion　ratio　but　was　minimally　influenced　by　the　longitudinal　corrosion　ratio.　The　specimen　exposed　to　corrosion　at　the　mid-height　yielded　plastic　hinges　at　both　the　bottom　and　middle　of　the　column.　©　2024　Elsevier　Ltd