Abstract: Mega-structure is a new kind of structural system for high-rise buildings. The main advantage of mega-structure is high capacity to resist lateral loads. Shanghai World Financial Center Tower is selected in the paper to study the features of Mega-structure. The lateral loads are resisted by a system containing mega-frame, reinforced concrete core and outrigger trusses. Shaking table model test is taken and a 3-D finite element analysis is carried out using ANSYS. The study demonstrates some dynamic characteristics of the mega-structure and some influencing factors, which might be useful for structural system selection.