Partially concrete encased composite girder with corrugated web was proposed to improve the structural mechanics performance of continuous girder under hogging moment. The bending behavior of concrete encased composite girders with corrugated web under two points symmetric loading was experimentally investigated. Experimental results show that the partially encased girder has superior bending strength and ductility compared to steel I girder, as local buckling of compressive flange is restricted by concrete encasement. In addition, prediction methods of bending strength under ultimate state were proposed based on the experimental failure mode and strain distribution. And the calculated bending strengths for steel and composite girders at ultimate state agreed well with the experimental results. The test findings and analytical methods were considered to be of special significance to the design of such partially encased composite girders with corrugated web.