This paper is focused on the research of seismic response of cylindrical latticed-intersectedthree-dimensional-beam-system (LITDBS) reticulated mega-structure with double-layers plane-plate grid sub-structures using response spectrum technique. The distribution law of dynamic internal forces of members in this new structure is researched firstly. Reasonable number of vibration modes recommended for use is discussed. Seismic behaviors of the structure under different directional seismic loads are analyzed; therefore the reasonable required components of seismic loads for seismic design are obtained. A series of geometrical parameters analysis are carried out at last. All the works will provide guides in theory for the use of this structure.