Civil structures means the economical structures . There are famous softwares to analysis and design and optimization of structures . Behavior of structures under loading specially lateral loading depend on two factors , soil condition under the structures and the type of analysis . We know that the structural softwares such as ETABS2000 can use to analysis and design but the soil under the structure can not modelled with this software truly. Interaction between the soil and structure means the influence of structure deformation on the soil below and counter . Interaction between the soil and short steel structures with X shape bracing was investigated in this article . The method of analysis that used in this article was the dynamic and the response spectrum type because the static analysis was not viewpoint the time . The time history mehod is the best method but difficult too. So used the response spectrum method for this research . The results showed clearly that the column forces decreases when we considered soil – structure interaction specially for the case of the soil was dense or stiff .