Owing　to　their　exceptional　durability　and　lower　total　life-cycle　cost,　reinforced　sea-sand　concrete-filled　(circular)　stainless　steel　tubular　(RSCFSST)　columns　offer　a　highly　viable　structural　solution　for　coastal　regions.　To　investigate　the　effects　of　stirrup　spacing　and　concrete　type　on　the　axial　compression　properties　of　circular　RSCFSST　columns,　eight　axial　compression　tests　were　conducted　on　three　types　of　specimens:　circular　RSCFSST　short　columns,　reinforced　normal　concrete-filled　stainless　steel　tubular　counterparts,　and　sea-sand　concrete-filled　stainless　steel　tubular　(SCFSST)　counterparts.　The　test　results　indicated　that　the　use　of　sea-sand　concrete　has　minimal　influence　on　the　axial　compression　behavior　of　the　circular　RSCFSST　column.　Furthermore,　the　circular　RSCFSST　columns　exhibited　superior　compression　resistance　and　ductility　compared　to　their　SCFSST　counterparts.　Subsequently,　a　finite　element　(FE)　model　of　the　circular　RSCFSST　column　was　developed　to　perform　mechanism　and　parametric　analyses.　Mechanism　analysis　highlighted　that　the　confinement　provided　by　stainless　steel　stirrups　significantly　enhances　both　the　bearing　capacity　and　ductility　of　core　concrete.　The　parametric　analysis　further　indicated　that　their　axial　compression　resistance　increases　with　increasing　concrete　compressive　strength,　steel　yield　strength,　steel　tubular　ratio,　or　volumetric　stirrup　ratio.　Based　on　these　findings,　new　simplified　models　to　forecast　the　axial　compression　resistance,　axial　compression　stiffness,　and　peak　strains　of　circular　RSCFSST　columns　were　suggested.　©　2025　Techno-Press,　Ltd.