In this study several practical limitations of Iranian current building code are addressed to SHA (Seismic Hazard Analysis) projects. The main concern of the present study is to propose a practical procedure for constructing smooth response spectra from peak values of ground motion. The dynamic amplification factors are calculated for horizontal and vertical components, considering the selected Iran’s strong motion records, and are compared with those proposed in the previous ones. The results and conclusions of this study are effective in the evaluation of Iranian present seismic code and can be used in SHA projects in Iran.