Abstract: This paper presents a simplified method of analysing a structure of tall building with wide space of ground floor.This structure is generally formed as a type of shearwall supported by beamcolumn system,and a type of combined system of the above with shear wall(deepened to ground)and walled frames.When the structures are subjected to lateral loads,the structure of ground and upper storeys can be looked upon as a beam with two spans, and finally this complicated structure is simplified as a rigid frame with one elastic joint.The method gives a clear physical idea and convenience of calculation which can easily be accepted and used by most of designers, especially for those who calculate by hands.