To　study　the　seismic　behavior　of　steel　reinforced　concrete　columns　with　various　cross-sectional　shapes,　steel　shapes,　and　concrete　strengths,　four　large-size　specimens　were　designed　and　an　experimental　study　was　conducted.　High-strength　concrete　can　effectively　improve　the　bearing　capacity,　stiffness,　and　energy　dissipation　capacity　of　proposed　specimens,　while　the　specimens　with　high-strength　concrete　showed　more　serious　compressive　damage　and　lower　ductility　index.　The　square　specimens　showed　more　significant　bearing　capacity　decline　after　the　peak　point　than　rectangular　specimens　and　the　ductility　indexes　were　smaller.　However,　the　ductility　indexes　and　peak　drift　ratios　of　all　specimens　were　larger　than　3.58　and　1/50,　which　still　met　the　suggested　values　in　the　related　code.　The　ductility　indexes　and　residual　deformations　of　square　specimens　with　high-　and　low-strength　concrete　were　more　closed　than　those　of　rectangular　specimens　with　high-　and　low-strength　concrete,　indicating　that　the　proposed　square　specimens　had　more　stable　deformation　capacity　under　different　concrete　strength.　Furthermore,　considering　the　different　confinement　effects　of　concrete　in　different　regions,　the　stress–strain　relationships　of　concrete　in　different　regions　were　calculated　individually　and　a　modified　fiber-based　method　was　proposed.　The　calculated　results　showed　good　agreement　with　the　experimental　results,　indicating　that　the　method　can　be　used　for　the　design　of　steel　reinforced　concrete　column　cross-sections.　©　2021　John　Wiley　&　Sons,　Ltd.