Concrete　filled　steel　tubular　(CFST)　structures　have　become　a　viable　alternative　to　reinforced　concrete　or　steel　structures　due　to　several　advantages.　One　of　the　most　important　is　the　confinement　effect　of　the　concrete　core　provided　by　the　steel　tube.　However,　this　beneficial　composite　action　will　be　probably　weakened　by　debonding,　so　reliable　formulations　to　predict　the　reduced　ultimate　resistance　are　needed.　In　this　paper,　a　review　of　existing　specifications　and　experimental　tests　carried　out　on　compressed　circular　CFST　columns　with　and　without　debonding,　is　given.　Accordingly,　more　circular　CFST　long　specimens　with　debonding　should　be　necessary　to　understand　the　combined　influence　of　slenderness　ratio,　load　eccentricity　ratio　and　confinement　factor　on　the　reduction　coefficient　(KD)　of　ultimate　load　capacities　(Nu).　The　combined　influence　of　arc-length　ratio　and　thickness　of　circumferential　debonding　gap　on　KD　should　be　further　studied　by　experimental　tests.　Moreover,　the　existing　formulae　for　KD　and　Nu　show　a　low　accuracy　in　predicting　the　test　results　and　should　be　improved.　To　this　aim,　an　evolutionary　polynomial　regression　(EPR)　MOGA-based　methodology　was　performed　to　obtain　more　accurate　formulations　for　Nu　and　KD　of　circular　CFST　columns　with　debonding.　The　formulae　extracted　from　the　Pareto　front　of　non-dominated　solutions,　demonstrate　good　accuracy,　higher　than　the　ones　in　literature.　The　proposed　models　are　consistent　with　the　physical　interpretation　of　the　studied　phenomenon　according　to　which　Nu　and　KD　decrease　as　debonding　parameters　increase　and　can　be　used　to　calculate　the　real　resistance　of　CFST　structures.