Viewing from the energy angle and taking the Beijing depression as an example, this paper studies the effects of underlying geological structures, mainly bedrock topography and bedrock faults, on the propagation of seismic waves and discusses the effects of the overlying soil layer on seismic waves. From the study, some conclusions are drawn as follows: In the paper, the idea of expressing the intensity of seismic waves in terms of energy is put forward. Comparison between the expressions of the seismic wave intensity in terms of energy and the maximum amplitude shows that the former is better than the latter in reflecting the effects of underlying geological structures on seismic wave propagation.