Concrete-filled　square　stainless　steel　tubes　(CFSSST),　which　possess　relatively　large　flexural　stiffness,　high　corrosion　resistance　and　require　simple　joint　configurations　and　low　maintenance　cost,　have　a　great　potential　in　constructional　applications.　Despite　that　the　use　of　stainless　steel　may　result　in　high　initial　cost　compared　to　their　conventional　carbon　steel　counterparts,　the　whole-life　cost　of　CFSSST　is　however　considered　to　be　lower,　which　offers　a　competitive　choice　in　engineering　practice.　In　this　paper,　a　comprehensive　experimental　and　numerical　program　on　24　CFSSST　stub　column　specimens,　including　3　austenitic　and　3　duplex　stainless　steel　square　hollow　section　(SHS)　stub　columns　and　9　austenitic　and　9　duplex　CFSSST　stub　columns,　has　been　carried　out.　Finite　element　(FE)　models　were　developed　to　be　used　in　parametric　analysis　to　investigate　the　influence　of　the　tube　thickness　and　concrete　strength　on　the　ultimate　capacities　more　accurately.　Comparisons　of　the　experimental　and　numerical　results　with　the　predictions　made　by　design　guides　ACI　318,　ANSI/AISC　360,　Eurocode　4　and　GB　50936　have　been　performed.　It　was　found　that　these　design　methods　generally　give　conservative　predictions　to　the　ultimate　capacities　of　CFSSST　stub　columns.　Improved　calculation　methods,　developed　based　on　the　Continuous　Strength　Method,　have　been　proposed　to　provide　more　accurate　estimations　of　the　ultimate　resistances　of　CFSSST　stub　columns.　The　suitability　of　these　proposals　has　been　validated　by　comparison　with　the　test　results,　where　a　good　agreement　between　the　predictions　and　the　test　results　have　been　achieved.　study;　stub　column　tests