Abstract: The cyclic tests were conducted on three 1/3 scaled three-story coupled steel plate shear wall specimens. Unstiffened, vertical channel stiffened, and grid stiffened steel plates were employed as web plates of specimens, respectively. Vertical boundary elements of the coupled steel plate shear walls were concrete-filled square steel tubes. Force-displacement hysteresis curves and failure modes of the specimens were obtained. Envelop curves, stress development, ductility, and energy dissipation were investigated. The finite element analysis software ABAQUS was used to simulate the behavior of specimens. The results show that unstiffened and vertical channel stiffened web plates buckle before yielding, and grid stiffened web plates yield before buckling. Coupling beams and horizontal boundary elements yield after the yielding of web plates. Concrete-filled square steel tubes yield early and have good strength and inelastic deformation. The specimen with unstiffened web plates has the least strength and energy dissipation. The specimen with vertical channel stiffened web plates is the next. The specimen with grid stiffened web plates has stable hysteretic characteristics. The strength of specimens with grid stiffeners and vertical channel stiffeners is increased by 11.7% and 6.9%, respectively compared with that of the unstiffened specimen. The equivalent viscous damping coefficient of specimens with grid stiffeners and vertical channel stiffeners is increased by 65.9% and 19.9% compared with that of the unstiffened specimen. The ductility factors of three specimens are greater than 4.5. It indicates that the coupled steel plate shear walls with different stiffeners have excellent ductility. The analysis results are in good agreement with the experimental results. The stiffener has little influence on the internal force of the coupling beams and boundary elements but increases the strength of the web plates. Compared with two single pier steel plate shear walls, the strength and energy dissipation of the coupled steel plate shear wall have an increase greater than 20%.