Based on the theory of wave and the Snell theorem, propagation characteristics of seismic wave, three kinds of elastic body waves, is studied when they pass through soil/elastic solid medium including elastic thin plan intercalation in half-space. The analytic solution of the amplitude rate is the rate of the amplitude of the wave behind the intercalation to that of the incident wave. Compared with the field data, the analytic results are beneficial, affected by soft clay stratum, at the Nankai District of Tianjin Municipality caused by the 1976 Tangshan earthquake (had a magnitude of 7.8). In this area, however, damage of the buildings was generally minor, about 50%, with the Heping District near Nankai
