The stiffness degradation model of SRC frame is determined based on the experimental data of a SRC frame. Combined it with the stiffness degradation rule in different deformation phases of RC core wall, and RC frame, it is advised that a / three- stage seismic design0 process be adopted in frame- core wall structure design through response spectrum analysis design means based on stiffness degradation.And the realization step of the means is introduced, whose applicability in / dual system0 is tested by a calculation illustration.In the end, some rules of the inner force redistribution in frame- core wall structure under earthquake load are introduced, and the possible failure mode of frame column is discussed.