In this paper, measured blasting seismic waves and ideal sine waves of different dominant frequencies are separately loaded on the three-freedom elastic system in vertical direction. The dynamic response under every blasting seismic wave in vertical direction is calculated with central impulse method by programming on the computer. Changes of peak values of all the structural dynamic response are analyzed to discuss the specific effect of blasting seismic wave frequency on dynamic response of the three-freedom elastic system. The results show that the first natural frequency of the structure has dominant effect on peak values of dynamic response of structures. Other dominant frequencies with a larger proportion of total energy should be taken into consideration in addition to the basic main frequency when analyzing effect of blasting seismic wave frequency on structural dynamic response, for blasting seismic waves are complex signals of many frequencies.