Abstract: A total of 4 composite steel plate shear walls connected with frame beams under cyclic load were tested in present research. The influence of unrestrained strips (between concrete panel and steel angle) and stiffeners at the corner of steel plate was studied. The experimental results illustrated that welding stiffeners to the corner is an effective way to avoid the early failure of specimen and to improve the energy dissipation ability. Comparing to the specimens without stiffeners, the maximum storey drift ratio of specimen with stiffeners improved from 1/35 to 1/25, and the energy dissipation ratio increased by 35%. The reasonable unrestrained strip height is another important parameter in the design of composite steel plate shear wall.