In order to understand dynamic characteristics of the new-type flexible retaining walls constructed with soilbags, small-scale shaking table model tests were conducted on retaining walls constructed with soilbags filled with natural sands. The effects of three elements of earthquakes, input accelerations, vibration frequencies, and vibration durations, as well as the size of soilbags, on the retaining walls were investigated, and change patters of horizontal displacements, dynamic earth pressures, and accelerations were analyzed. The results show that displacements of retaining walls and pressure coefficients of dynamic earth increase with the increase of input accelerations and the decrease of vibration frequencies, while the acceleration response increases with the increase of both input accelerations and vibration frequencies. However, the effects of vibration durations on dynamic characteristics are relatively small. In addition, compared with retaining walls constructed with normal-size soilbags, the seismic performance of retaining walls constructed with larger bags is slightly poorer. However, larger soilbags can be used in areas with lower seismic requirements or projects with tight schedules because of their ease of construction and high efficiency.