Abstract: Combining the mechanical characteristics of a box girder with corrugated steel webs, this paper studies the transverse internal forces in a box-girder bridge with corrugated steel webs, and then proposes a mechanical analytical model for calculating transverse internal forces in box-girder bridges with corrugated steel webs, in which torsion is restrained by non-deformable surroundings and distortional warping is considered. Experimental testing and finite element analysis of the real box-girder bridge with corrugated steel webs was carried out; the result proves the validity of the proposed model. A comparative study using the requirements for transverse design in the Code for Designing Highway Reinforced Concrete and Prestressed Concrete Bridges (JTG D62-2004) indicates that increasing the bending moment coefficients can insure the safety of the transverse design of box-girder bridges with corrugated steel webs.