Concrete　filled　steel　tube　(CFST)　structures　have　been　used　widely　in　high-rise　buildings　and　bridges　due　to　the　efficiency　of　structurally　favourable　interaction　between　the　steel　tube　and　the　concrete　core.　In　the　current　design　codes　only　one　loading　condition　in　the　column　members　is　considered,　i.e.,　the　load　is　applied　on　the　steel　tube　and　concrete　core　at　the　same　time.　However,　in　engineering　practice　the　tube　structures　may　be　subjected　to　various　loading　conditions　such　as　loading　on　the　concrete　core　only,　preloading　on　the　steel　tube　skeleton　before　filling　of　concrete　core,　and　so　on.　In　this　research,　a　series　of　comparative　experiments　were　carried　out　to　study　the　structural　performance　of　concrete　filled　circular　steel　tube　columns　subject　to　four　concentric　loading　schemes.　Then,　a　generalized　prediction　method　is　developed　to　evaluate　the　ultimate　load　capacity　of　CFST　columns　subject　to　various　loading　conditions.　It　is　shown　that　the　predictions　by　the　proposed　method　agree　well　with　test　results.