To　study　the　bending　resistance　characteristics　of　steel　reinforced　ultra-high　performance　concrete　(SRUHPC)　beams　with　rectangular　section,　four　SRUHPC　beam　specimens　with　rectangular　section　were　fabricated,　with　the　reinforcing　ratios　ranging　from　0.　8%　to　1.1%　and　the　steel　ratios　ranging　from　8.7%　to　15.6%.　The　embedded　steels　arc　Lshapcd,　inverted　T-shaped,　and　H-shaped.　Flexural　ultimate　capacity　tests　were　conducted　to　analyze　the　damage　mechanism　and　failure　modes　of　SRUHPC　beam　specimens　with　rectangular　section.　Based　on　test　results　and　theoretical　derivations,　a　calculation　method　for　the　flexural　capacity　of　SRUHPC　beam　with　rectangular　section　was　proposed.　The　flexural　capacities　of　21　SRUHPC　beam　specimens　with　rectangular　section　and　111　finite　element　calculation　models　were　calculated,　and　the　calculation　results　were　compared　with　the　test　and　finite　element　calculation　values.　Analysis　results　indicate　that　the　failure　modes　of　SRUHPC　beam　specimens　with　rectangular　section　arc　all　reinforced　failures　due　to　bending.　The　steels　and　longitudinal　tensile　reinforcements　yield　successively,　followed　by　the　crushing　of　the　UHPC　in　the　compression　zone.　The　steels　and　UHPC　work　well　together　until　the　specimens　failure.　The　specimens　with　embedded　inverted　T-shaped　and　H-shaped　steels　exhibit　higher　capacities　and　stiffnesses　compared　to　those　with　embedded　I-shaped　steel,　and　they　demonstrate　better　crack　resistances.　Compared　with　other　specimens,　under　the　same　load,　the　strains　and　strain　development　rates　of　longitudinal　reinforcements,　UHPC,　and　steels　in　specimens　with　embedded　H-shaped　steels　are　relatively　smaller.　Therefore,　setting　upper　and　lower　flanges　in　the　steel　within　SRUHPC　beam　with　rectangular　section　contributes　to　enhancing　the　flexural　performance　of　the　composite　beam.　The　calculated　results　obtained　by　the　proposed　method　show　mean　ratios　of　0.　972　and　1.　035　compared　with　the　test　and　finite　element　calculation　values,　with　variances　of　0.　009　and　0.　002,　respectively.　The　research　results　can　provide　theoretical　supports　for　the　promotion　and　application　of　SRUHPC　beams　with　rectangular　section　in　practical　engineering　and　the　formulations　of　codes　and　regulations.　3　tabs,　21　figs,　30　refs.　©　2024　Chang＇an　University.　All　rights　reserved.