JGJ　138　2016,　CH　3-78,　YB　9082　2006,　AISC　360-16,　and　YE　Lie-ping＇s　formulas　were　used　to　calculate　the　ultimate　flexural　capacities　of　51　collected　specimens　of　steel　reinforced　concrete　(SRC)　beams　with　rectangular　sections.　The　calculated　results　were　compared　with　the　test　values.　The　ranges　of　parameters　of　the　collected　specimens　and　the　reasons　for　the　calculation　errors　of　the　existing　calculation　methods　were　analyzed.　The　limitations　of　the　existing　calculation　methods　were　discussed　in　terms　of　the　calculation　theory　and　other　aspects.　Theoretical　derivations　were　performed,　and　a　method　for　calculating　the　ultimate　flexural　capacities　of　SRC　beams　with　rectangular　sections　was　proposed,　and　the　ultimate　flexural　capacities　of　the　collected　specimens　were　calculated　by　using　the　proposed　method.　Analysis　results　show　that　some　deviations　arc　found　between　the　calculated　values　obtained　by　the　existing　calculation　methods　and　the　test　values.　The　height　value　of　the　compression　zone　in　CH　3-78　is　not　appropriate,　and　the　calculation　error　of　this　method　increases　with　the　increase　in　concrete　strength.　The　impact　of　the　relative　relationship　between　the　neutral　axis　and　the　position　of　the　structural　steel　on　the　calculation　results　is　not　considered　in　JGJ　138—2016,　and　limitations　exist.　YB　9082—2006　and　AISC　360-16　do　not　take　into　account　the　interaction　between　structural　steel　and　concrete　or　the　arrangement　of　the　structural　steel.　The　YE　Lie-ping＇s　formulas　produce　conservative　results.　The　average　ratio　of　the　values　calculated　by　the　proposed　method　for　the　ultimate　flexural　capacity　to　the　test　values　of　specimens　is　0.　953,　with　a　variance　of　0.　015.　The　calculated　values　agree　well　with　the　test　values.　The　steel　ratios　of　the　collected　SRC　beam　specimens　range　from　1.　77%　to　5.　77%,　which　is　smaller　than　the　reasonable　steel　ratio　range　suggested　by　YB　9082—2006.　Therefore,　it　is　necessary　to　carry　out　further　supplementary　tests　of　specimens　with　high　steel　ratios　in　the　future,　so　as　to　improve　the　calculation　method　for　the　ultimate　flexural　capacity　of　SRC　beams　with　rectangular　sections.　1　tab,　10　figs,　31　refs.　©　2024　Chang＇an　University.　All　rights　reserved.