The steel plate girder with the corrugated web is widely used in many applications because it has many advantages. It has a high resistance against lateral-torsion buckling compared with another flat web girder with the same steel weight. The design method for calculating the lateral-torsional buckling strength of corrugated webs girders is not provided in the current standards and specifications. This paper focuses on the strength of corrugated web girders against lateral-torsional buckling and presents the theoretical and finite element analysis to study the behavior of this type of girders. The Nonlinear finite element analysis is carried out using ANSYS. The influence of various parameters (web thickness, web height, corrugation angle, corrugation width, and corrugation shape) is considered in this study. Where there are a few approaches such as Linder, Moon, and Zhang. explain how to determine the warping constants of corrugated web beams therefore, the applicability of these approaches is evaluated in this study. It is found that the formulas of Moon and Zhang are more accurate than the Linder formula except in the case of beams with a ratio between web height and flange width equal or less than 2.0. The applicability of using the Euro-code equations of the lateral-torsional buckling moment for plate girders with flat webs in cases of girders with corrugated webs is studied. It is concluded that the Euro-code equations can be used for corrugated web girders with a good agreement after using Moon's or Zhang's formula to calculate the warping constant.