Abstract: A discrete wavelet-based stochastic formulation has been presented in this paper for the seismic analysis of sliding structures. The ground motion has been modeled as a non-stationary process by using discrete wavelet transform. The proposed formulation is based on replacing the non-linear system by an equivalent linear system with time-dependent properties. The expressions of the instantaneous damping, mean square velocity response and slip displacement response have been obtained in terms of the input discrete wavelet coefficients. In comparison with the Monte-Carlo method, it is shown that the non-stationary earthquake responses of sliding structures can be calculated correctly by the discrete wavelet-based analysis method. Finally the maximum root mean square slip displacement spectra of the base-isolation structure are presented.