This paper studies the possibility of localizations for frame structures in static and dynamic analysis. A finite element model is used in which the sections resisting force is calculated using an introduced differential hysteretic model. A microplane constitutive law for concrete and bi-linear elasto-plastic material model for reinforcements evaluates parameters of the differential hysteretic model in sections. The sensitivity to probable changes in ground motion characteristics is assessed by a nonstationary ground motion generation process to obtain excitations with approximately the same amplitude and frequency content evolution as those of a base ground motion. The procedure is applied in two case studies and possibility of localization in response is investigated. A measure for the probability of occurrence of this behavior in code-designed structures is obtained. This study indicates that localization and resulting early collapse of structure is possible. It is concluded that some modifications in design code provisions are required.