A building that is composed of coupled shear walls with dampers, CFT columns, and flat plate slabs is one of the types of buildings that can be reused, with low repair cost, after an earthquake. To evaluate the lateral load-deflection relation of the newly designed CFT column/flat plate connection, two series of experimental studies were carried out: lateral loading tests for interior column/slab connections, and element tests for torsional stiffness and strength. Lateral load-deflection behavior of the CFT column/flat plate connection were examined using macro models proposed in this study, and good agreements are obtained.