In　this　paper,　6　pieces　of　steel-concrete　composite　girders　with　externally　prestressed　tendons　were　tested　under　positive　moment　loading,　and　nonlinear　finiete　element　anaysis　were　also　conducted　to　explore　the　effects　of　concrete　strength,　degree　of　partial　shear　connections　on　the　ultimate　flexural　capacity,　deflection,　slip　property　between　the　concrete　and　steel　and　stresss　increments　of　external　prestressed　tendons.　Some　key　conclusions　can　be　extracted　from　the　experiments　and　analysis　and　listed　as　follows:　(1)　The　higher　concrete　strength　as　well　as　degree　of　shear　connection　will　result　in　the　increment　of　the　ultimate　flexural　capacity,　while　increment　of　external　prestressing　make　rare　contribution　of　the　ultimate　flexural　capacity　of　externally　prestressed　steel-concrete　composite　girders　for　positive　moments;　(2)　The　decrease　of　partial　shear　connection　will　increase　the　deformation　of　externally　prestressed　steel-concrete　composite　girder;　(3)　The　proposed　nonlinear　FE　model　can　better　predict　static　behavior　of　prestressed　steel-concrete　composite　girders　in　the　positive　moment　area,　and　the　results　from　testing　and　FE　analysis　can　correlate　very　well　with　each　other.