This paper investigates collapse prevention system for seismic resistant design in new construction and existing buildings. The collapse prevention system consists of slack cables, working in tandem with the main lateral-force resisting system to control the lateral displacements. The purpose of this system, is to restore the seismic performance of the initial structure from collapse prevention to life safety performance level, at the BSE-2 hazard which have a mean recurrence interval of approximately 2475 years. This system can also be used to improve the performance from life safety to immediate occupancy performance level, at the BSE-1 hazard which have a mean recurrence interval of approximately 475 years. To achieve the right results, a number of parametric studies, on the effect of the number of stories, the diameter of the cable and the amount of their initial loosening were performed, by providing structural analytical models. Analytical performance of archetypical 8-story, and 12-story steel-frame buildings employing collapse prevention systems indicate that collapse prevention systems substantially reduce the probability of collapse during Maximum Considered Earthquake (MCE) ground motions.