Abstract: The aseismic design method in Chinese code is not a real probability limit state design; the structural reliability is not applied in a structural system reliability level. A two-stage, full probability aseismic design method is put forward, which is based on a direct failure probability checking format. In this method, the failure probability is calculated by a numerical simulation method. During the first design stage, the strength reliability index of the member-level ultimate limit state under a minor earthquake is checked against the target reliability index, and meanwhile, the global elastic deformation reliability of a serviceability limit state under a minor earthquake and the global elastic-plastic deformation reliability of a lateral collapse limit state under a major earthquake are also checked. The two-level full probability aseismic design of a component and a structure are both accomplished. The design procedures of the full probability design method are brought forward, which are checked with a steel frame structure design example. The full probability aseismic design method based on reliability theory is an advanced method, which will be a developing trend of aseismic design.