Large　rupture　strain　(LRS)　fiber-reinforced　polymer　(FRP)　composites　with　an　ultimate　elongation　of　greater　than　5%　offer　superior　deformation　and　energy　dissipation　abilities　over　traditional　carbon　or　glass　FRP　when　used　them　in　lateral　confinement　of　concrete　under　the　same　confinement　level.　However,　a　flexible　model　for　predicting　the　stress-strain　relationship　of　concrete　columns　confined　with　LRS　FRP　is　not　yet　perfectly　developed,　especially　for　noncircular　columns　experiencing　nonuniform　confining　stress.　Accordingly,　an　extensive　database　of　LRS　FRP-confined　square　and　circular　concrete　columns　with　corner　radius　ratios　varying　from　0　to　1　was　employed　to　establish　a　unified　stress-strain　model.　This　model　not　only　includes　the　determinations　of　key　points,　but　also　attempts　to　define　the　threshold　confinement　level　to　distinguish　the　post-peak　strain-hardening　and　strain-softening　behaviors.　The　mathematical　expression　of　the　model　is　simple;　it　also　avoids　discontinuities　in　the　prediction　of　different　cross-sections.　The　proposed　model　is　verified　to　be　accurate　in　predicting　the　complete　stress-strain　curves　of　LRS　FRP-confined　square　and　circular　concrete　columns　with　hardening　and　softening　behaviors.　In　addition,　it　outperforms　the　existing　theoretical　models　in　predicting　the　ultimate　strength　and　the　ultimate　axial　strain.