Abstract: In this paper，a single-degree-of-freedom system is adopted to analyze and compare the exciting force passing through a flexible driving rod with the disturbance force passing through the elastic member. Particularly，the mechanism of how the attached structure influences the excited object is investigated. Both experiments and numerical simulation are conducted to determine the frequency range of the exciter and the applicability of a suspended excitation for a structure in free suspension. The results show that when the lowest operating frequency of the exciter is 3 to 4 times higher than the inherent mounted frequency，the suspended excitation is feasible，and the higher the excited frequency，the lower the influence from the disturbance force. On the contrary，when the excited frequency is lower than the inherent mounted frequency，the suspended excitation is no longer appropriate.