Abstract: It is firstly introduced the steps and parameters setting of the pushover analysis in SAP2000. Then, the soft-ware is used to finish the pushover analysis of an 8-story frame structure with large-span unbonded prestressed floor and a similar RC frame in an 8-degree seismic fortification intensity zone. With the purpose of evaluating the antiseismic performance of the prestressed structure, it is compared between the above two kinds of structures, including the base shear force-top displacement curves, the performance points, and the occurring sequence of the plastic hinges. The theoretical analysis and the calculating results indicate that when the buildings are regular and not too high, to compare with the similar RC structure, the prestressed frame structure has a better stiffness after cracks, a larger ultimate loading capacity, and a beam-hinge failure mechanism with better antiseismic performance.