Abstract: Based on the shear beam theory, the seismic response of bar tension in reinforced earth retaining wall under horizontal earthquake loads is investigated. In this study, the reinforced soil is regarded as macroscopically well-distributed composite material, and the reinforcement strip is regarded as reinforcing material. Based on the shear beam model, the shear strain of backfill soil under horizontal earthquake loads is obtained. The reinforcement strip moves with the soil body around, and the movement is simultaneously restricted by it. The destructive power of reinforcement strip depends on the size of its deformation, so the reinforcement strip can be simplified as one-dimensional elastic rod. In view of these assumptions, one can get the fact that the axial strain of reinforcement strip equals the horizontal shear strain of backfill soil. Furthermore, a dynamic tension equation is established by means of the Hooke's law to analyze the dynamic tension of reinforcement strip under the harmonic earthquake loads. The proposed method is used to a practical application to conduct the seismic analysis. At last, the method is analyzed by using the finite element software (ADINA) to verify its rationality. The results of show that the proposed method is safe and reliable.