The widespread use of plate structures in construction projects due to their lightness, strength and economic efficiency doubles the importance of using them. In this study, in order to reduce the upward trend of the thickness of concrete gravity retaining walls and consequently reduce the upward trend of the materials consumed for increasing the height of the wall, flat slabs are adapted to concrete gravity retaining walls and a new type of lightweight retaining wall is proposed. Then, an attempt has made to provide the basis of plate theory and the physical and mathematical aspects of the topics and its application in the studies conducted for the new retaining wall, and the governing equations for the proposed problem state is present. The results show that the new retaining wall will be significantly more economical in terms of concrete consumption. In general, in this study, a new method based on mathematical principles presented for calculating and analyzing a lightweight retaining wall composed of flat slabs.