Abstract: Based on the basic principles of dynamic analysis with finite elements, an method to analyze the non-stationary stochastic seismic responses of the underground structures was studied by using the impulse-response function and the principles of Fourier transform. The earthquake loads were taken into account as non-stationary random process in this paper. A numerical example was used to compute the displacement and stress root-mean-square responses of a tunnel under the non-stationary random earthquake loads with intencity of 7 degrees.