In consideration of shear lag and shear deformation effects, It was proposed an approach of analyzing thestatic characteristics of T-beams generally used in projects. A new warping displacement mode of T-beams was chosento meet the axial self-equilibrium condition for corresponding stress, three generalized displacement functions wereemployed in analyzing static characteristics of the thin-walled T-beams with wide flanges by calculus of variations, thedifferential equations and the corresponding natural boundary conditions of the T-beams are induced based on theminimum potential principle. According to the fundamental differential equations and the corresponding naturalboundary conditions, the static characteristics of thin-walled T-beams are discussed. The finite element solutions werecompared with the analytical solutions and verified the validity of the proposed approach.