Prestressed　box　girder　is　the　main　structural　form　of　reactive　powder　concrete　(RPC)　bridge.　To　understand　the　flexural　behavior　of　prestressed　box　girder,　a　finite　element　model　is　built　using　the　ANSYS　software　to　analyze　the　behaviors　of　girder,　such　as　the　load-displacement　relationship,　cracking　and　ultimate　load.　It　is　found　that　the　FEM　analyzing　results　were　in　good　agreement　with　the　experimental　results.　FEM　analysis　based　on　strength　parameters　of　concrete　also　indicates　that　the　initial　cracking　load,　reinforcement　yielding　load　and　ultimate　load　of　RPC　girder　can　be　improved　about　34.1%,　34.3%　and　35.1%,　respectively,　compared　to　the　normal　concrete　girders.　Furthermore,　the　calculation　method　for　cracking　moment　of　RPC　box　girder　was　studied.　It　is　found　that　in　the　Chinese　Code　JTG　D62-2004,　the　material　properties　of　RPC　can＇t　be　accurately　reflected　by　the　section　plasticity　influence　coefficient,　r,　and　the　calculation　method　shall　not　be　employed　because　the　calculation　results　are　much　larger　than　the　experimental　results.　Hence,　a　calculation　method　was　proposed　for　the　cracking　moment　of　prestressed　RPC　girder,　and　the　ratio　of　calculation　results　and　test　results　of　multiple　girder　specimens　may　range　from　0.91　to　0.96.　It　is　demonstrated　that　the　proposed　method　can　meet　the　requirement　of　engineering　calculation　precision,　and　can　be　referred　in　the　design　of　prestressed　RPC　box　girder.　©,　2015,　Editorial　Office　of　China　Civil　Engineering　Journal.　All　right　reserved.