To　study　the　serviceability　of　ultra-high　performance　concrete　(UHPC)　beams　reinforced　with　high　strength　steel　bars,　the　flexural　properties　of　six　UHPC　beams　were　tested.　Then　the　change　law　of　load-deflection　of　the　UHPC　beam　was　concluded,　the　cracking　moment,　the　short　term　stiffness　and　cracking　width,　and　the　calculation　methods　were　summarized.　Based　on　the　code　for　design　of　concrete　structures　(GB　50010-2010),　the　cross　sectional　plastic　coefficient　influencing　the　regression　equation　of　UHPC　beam＇s　cracking　moment　was　concluded,　the　rebar　nonuniform　coefficient　of　UHPC　beam,　the　internal　lever　arm　coefficient　of　cracking　cross　section,　and　the　average　integrated　strain　coefficient　were　ascertained　to　calculate　the　beam＇s　short　term　stiffness.　The　beam＇s　short　term　stiffness　was　calculated　and　compared,　based　on　the　adjusted　calculating　method　for　steel　fiber　reinforced　concrete.　In　addition,　a　modified　cracking　width　calculation　formula　was　generated.　©,　2015,　Editorial　Board　of　Journal　of　HEU.　All　right　reserved.