Abstract: Containment is the enclosure structure of reactor building for nuclear power plant (NPP), which prevents the leakage of radioactivity material out of NPP, when accidents occur. It is the key component for safety of the nuclear power plant. So it must be designed to resist the load under severe accident. Earthquake is one of potential natural disaster during the plant service life. And earthquake may result in severe accident. Seismic analysis should be performed for the containment. Prestressed concrete containment should be designed to remain functional under SSE. This thesis achieves the containment’s earthquake-resisdance capacity by finite element analysis, to get the displacement, stress and inner force of structure under SSE. The containment structure is determined to be adequately safe. The design can meet the category Ⅰ requirement of nuclear power plant.