Abstract: Side-plate joints for walled concrete-filled steel tubular column and steel beam are proposed. In order to study the seismic performance of the joint, the quasi-static tests of three full-size side-plate joint specimens were carried out. The failure pattern, hysteretic curve, skeleton curve, ductility, energy dissipation capacity, stiffness degradation and strain of the joint panel were analyzed. The results are as follows. The joint panels of three specimens remain elastic; the plastic hinge failure occurs at the beam end of side-plate joint specimens meeting the horizontal and vertical strength ratio requirements; the joint specimens with plastic hinge occurring at beam ends have good deformation performance and energy dissipation capacity, while the side-plate joints whose horizontal or vertical strength ratios are less than 100% undergo brittle failure. Based on the experimental study and the internal force transmission mechanism at beam ends, three failure modes of side-plate joint outside the joint panel and corresponding discriminant formulas were put forward, which were basically consistent with the experimental results and could be used as reference for engineering design.