In　order　to　study　the　influences　of　prestressing　degree　on　curved　box-girder　bridges,　180　two-span　curved　box-girder　bridge　models　were　built　by　taking　bridge　length,　central　angle　and　prestressing　degree　as　parameters.　Data-fitting　was　made　with　two-step　one-parameter　method,　resulting　in　experimental　formulas　of　stresses　and　unit　displacements　in　control　sections　under　limit　states,　so　variation　trends　and　degree　varying　with　prestressing　degree　were　studied.　Formulas　of　prestressing　degree　in　section　were　proposed;　two　indexes　were　advised　to　reflect　the　variation　trend　and　degree　of　structural　reactions　varying　with　prestressing　degree.