Abstract: By adopting exact dynamic stiffness matrices of a fluid-saturated soil layer and a half-space, an 1-D equivalent linear analysis method is proposed to solve the seismic response of a horizontally layered fluid-saturated poroelastic half-space due to the incident of inclined P and SV waves. By degenerating saturated soil to dry soil, and by comparing the degenerated results with those by 2-D finite element program FLUSH, the accuracy of the method is verified. Through taking a typical fluid-saturated site in Tianjin city as a numerical example, this paper compares the linear and nonlinear seismic responses of the site, and the nonlinear seismic responses between a fluid-saturated site and a dry site due to the incident of P and SV waves, and discusses the effects of incident angle and permeable boundary conditions on the peak ground acceleration of the fluid-saturated site. Some basic laws about the nonlinear seismic response of a fluid-saturated site are summarized.