In　order　to　investigate　the　feasibility　of　high　strength　rebars　used　in　UHPC　reinforcement,　a　flexural　performance　experiment　of　prestressed　beams　was　conducted.　The　variable　parameters　investigated　include:　type　of　non-prestressed　rebars,　reinforcement　ratio　and　level　of　prestress.　Experiment　results　show　that　increasing　the　prestressing　reinforcement　ratio　or　prestress　control　value　of　the　tendons　can　significantly　improve　the　beams　crack　resistance.　Higher　prestressing　level　can　be　achieved　for　UHPC　beams　reinforced　with　HRB500　unlike　conventional　concrete.　HRB500　rebar　has　little　effect　on　cracking　load　but　significantly　improves　the　yield　and　ultimate　loads　since　its　excellent　properties　are　fully　utilized.　Comparing　beams　reinforced　with　HRB500　and　beams　with　HRB335　reinforcement,　denser　microcracks　are　formed　for　UHPC　beams　with　HRB500,　moreover　crack　propagation　is　slower　and　crack　width　is　smaller,　not　exceeding　0.15mm　in　serviceability　limit　state.　Considering　the　influence　of　fiber　reinforced　UHPC　plastic　deformation　on　the　stress　distribution,　a　formula　for　the　calculation　of　the　initial　cracking　load　was　established.　From　the　simplified　UHPC　constitutive　model,　the　stress　in　the　tension　and　compression　zone　is　calculated　according　to　the　equivalent　rectangular　concrete　stress　distribution.　The　calculated　and　the　experimental　values　of　the　bending　capacity　are　in　good　agreement,　and　can　provide　reference　for　the　theoretic　analysis　and　design　of　UHPC　beams.