Abstract: Structural system reliability is an important indicator for seismic performance assessment of reinforced concrete (RC) frame structures and the evaluation basis for reinforcement of existing RC building structures. This paper is concerned with the development of a method to evaluate the structural system reliability of RC frame structures which can be effectively evaluated by using the ultimate moment carrying capacity at the ends of the bottom columns of RC frame structures. The pushover method is first employed to analyze RC frames, and by studying the influence of the ultimate moment carrying capacity of the bottom columns on the Pushover curve the structural failure response surface can be calculated from the reference points on the Pushover curve. This method is applied to estimate the system reliability of a RC frame. The numerical results obtained using the current method are compared with those predicted using the response surface method and Monte Carlo method. It is demonstrated that the proposed method is more computationally efficient and better in system reliability assessment.