This paper gives the basic methods for the analysis of the seismic response of viaduct based on elastic-plastic response spectrum method, and established indicators correspond with the method of strength, deformation, basic displacement and other performance. Practical example shows that the elastic-plastic response spectrum analysis response can be careful examining structure of each target in strong earthquake action value, and compare with the nonlinear time-history analysis, the method is concise, efficient, stable, and has the statistical significance of spectrum analysis, that can be used as a city track traffic high bridge and practical method.