Abstract: By means of member-storey model, a new method is proposed to study the time-history reliability of aseismatic structures under frequent earthquake. The improved pseudo variable method for static reliability analysis of structures, finite element techniques and time-history analysis are adopted in the new method. The randomness of structural parameters, earthquake motion and the effects of earthquake action and static loads are taken into account in the present model. Consequently, the time-history reliability index)β(t)for load bearing capacity of every member and lateral deformation capacity of aseismatic structures at any time can be obtained. As an example, the time-history reliability of a three-story frame under frequent earthquake is examined using the Monte Carlo Method as well as the present method. The effectiveness of the present method is verified.