To　study　the　seismic　behavior　and　influencing　factors　of　reinforced　ultra-high　performance　concrete　(UHPC)　columns,　by　taking　carbon　fiber　reinforced　polymer　(CFRP)　sheet　winding,　steel　strength,　and　shear　span　ratio　as　variables,　tests　were　carried　out　on　an　ordinary　steel　reinforced　UHPC　column,　an　ordinary　steel　reinforced　UHPC　column　wound　with　CFRP　sheet,　and　three　high-strength　steel　reinforced　UHPC　columns　under　low　frequency　cyclic　loads.　The　failure　mode,　load-displacement　curves,　ductility,　and　energy　dissipation　capacity　of　the　specimens　were　analyzed.　Results　show　that　the　ductility　and　energy　dissipation　capacity　of　the　reinforced　UHPC　columns　with　shear　span　ratio　of　1.5-4.0　were　good.　Under　CFRP　sheet　winding　or　large　shear　span　ratio,　the　failure　mode　of　the　specimens　changed　from　shear　compression　failure　to　bending　shear　failure,　and　the　ductility　was　significantly　improved.　The　bearing　capacity　and　ductility　of　the　specimens　were　improved　by　increasing　the　strength　of　the　longitudinal　steel　and　stirrups　of　the　UHPC　columns.　The　working　capacity　of　the　ordinary　stirrups　was　poor　after　cracking,　so　it　is　suggested　that　the　shear　members　of　UHPC　should　be　reinforced　with　stirrups　with　yield　strength　above　600　MPa.　Based　on　the　truss-arch　model,　the　calculation　formula　of　shear　capacity　of　reinforced　UHPC　columns　was　established　by　taking　account　of　the　tensile　contribution　of　steel　fibers　and　the　influences　of　axial　compression　ratio　and　shear　span　ratio.　The　calculated　values　agreed　well　with　the　test　results,　which　can　provide　reference　for　the　design　of　UHPC　structures.　Copyright　©2021　Journal　of　Harbin　Institute　of　Technology.All　rights　reserved.