Abstract: Many high-order theories for plate bending have been presented, in which the transverse shear deformation is included. Although those refined plate theories retain high accuracy for plate analyses, their governing equations are usually quite complicated and arenot suitable for practical use. In addition, few researchers carefully discuss influence of estimation of lateral loads. In this paper, we pay attention to constitution of lateral loads of plates. Especially we formulate the new theory for plate bending, in which the effect of a body force is distinguished from that of surface tractions. As a result, we can establish a quite simple plate theory including not only transverse shear deformation but also transverse normal stress effect. It follows form the present numerical examples that the new theory presented here is as accurate as Lo-Christensen-Wu's theory for thick plate bending.