Abstract: The lateral wall deflection is an important cause which results in ground surface displacement and settle-ment around an excavation. This paper examines the influence of a number of factors affecting the lateral wall de-flection in soft一clay using the finite element methed, such as the factor of safety against basal heave,the depth ofexcavation,the wall stiffness and the undrained shear strength of clay.A simplified method to estimate the lateralwall deflection is proposed. Deflections calculated by this method agree fairly with the field records and published da-ta.