Abstract: In this article, the author analyses the effect of media of the one-phase soil, unsaturated soil, saturated soil and soil layers structure with different modulus on seismic wave propagation, using dynanoic differential equations of two-phase media, and explicit finite element lumped-mass method with artificial transmitting boundary. It is shown that the character of media play an important role in P-wave propagation while the structure of soil layers has obvious effect on SV wave propagation. In the end, the author also illustrates that if the soil is laterally to unhomogeneous, the 1-D analysis would conduce to considerable error.