The behavior of soil retaining structures during earthquakes is investigated. Seismic excitation imparts inertial forces to the soil retaining system, and, once the seismic acceleration reaches the yield level, the structure exhibits permanent displacements. This is typically associated with appearance of a shear band in the backfill. The application of the kinematic approach of limit analysis is briefly discussed. A specific example of a retaining wall with one distinct shear band is then presented. The inclination of the shear band is found to be dependent on the acceleration amplitude of the seismic excitation, per classical earth pressure theory. Also, it was found that the inclination of the shear band does not remain stationary, but rather changes throughout the shaking in response to the variation in the acceleration amplitude of the excitation. This phenomenon is illustrated by results from both a physical experiment and a numerical prediction, which indicate a distinct change in the shear band inclination during seismic excitation, leaving a clear pattern of "shear banding".