Abstract: A plane steel frame and its damped frame with double flanged rigid connections containing core tube were proposed in this paper and their substructures were designed to conduct pseudo-dynamic tests. Test results such as hysteretic behavior, strain variation of typical positions, lateral stiffness and energy dissipation capacity of both frames were comparatively analyzed to study their seismic performances. The results show that under the actions of 8-degree frequent earthquake and fortification earthquake, the intermediate column with friction damper can provide certain lateral stiffness, limit story drift response, mitigate and even avoid the plastic damage of the structure. Under the actions of 8-degree rare, 8-degree (0.30 g) rare and 9-degree rare earthquake, the friction damper can provide stable energy dissipation and effectively delay the plastic damage of the structure. The stiffness and energy dissipation capacity of the damped frame are superior to those of the plane steel frame, the double flanged rigid connections of both frames present favorable seismic performance and the seismic performance of double flanged rigid connections of the damped frame is superior to that of the plane steel frame.