The effect of soil and structure interaction improves the accuracy of seismic analysis of structures. In analyzing of soil-structure interaction, the flexibility of the soil on which the structure rests is considered. A very useful mechanism for dissipating energy is provided when a shallow foundation undergoes inelastic sliding, settling, and rocking movements under earthquake loading. In this study, the effect of soil-structure interaction on the seismic behavior of squat and slender shear walls has been investigated. For this purpose, shear walls with different height to length ratios, including squat and slender walls, considering a flexible shallow strip foundation with inelastic behaviour were modelled in the Opensees software and the nonlinear static analyses were used to evaluate the seismic response of the shear walls. This study is based on a differentiated look at structural elements with different dynamic characteristics in dealing with soil-structure interaction phenomena. Considering the importance of flexural-shear interaction in the behavior of shear walls, the walls have been modeled by considering flexural and shear interaction. It was shown that the considering the soil-structure interaction increases the period and the maximum drift of structure and reduces the base shear. In comparing the performance of squat and slender shear walls with including the soil-structure interaction, the increase in the period of squat shear walls was greater than slender shear walls. In the study of the percentage reduction of base shear by including soil-structure interaction, the percentage reduction in base shear increased with increasing the height to length ratio of the wall.