Based on the regularity of the influence of foundation parameters upon the surface wave dispersion curve, this paper presents the surface wave spectral analytical method in which the dispersion curve of the measured surface wave velocitias is used to make inverse analysis of stratigraphic shear wave velocities of the foundation. The method has some remarkable advantages:it is rapid in speed and good in convergence, and the parameters obtained can reflect the character of actual fondation soil mass. Therefore, it is of practival value in foundation treatment and quality evaluation of expressway surface.