The first part of this paper provides a theoretical framework on the subject of capacity spectra and its usefulness in studying the seismic vulnerability of buildings. Then, the works of some researchers, which have moved forward in the direction of setting the parameters of those curves, are reported and theirs most important conclusions are highlighted. After that, the models that have been used in this research together with theirs capacity spectra are introduced. Finally, techniques for setting parameters are applied on those curves and the most important results and conclusions are presented.