A continuum model with micro-structures is introduced to replace the layered media which consist of alternating laminae of two materials in the analysis of their mechanical behaviors. The continuum theory is employed to study surface-wave propagations in layered media. Dispersion equations according to the continuum theory are obtained and dispersion curves are computed. For a relatively simple laminated medium, exact dispersion curves are also worked out for comparison. It is found that the continuum theory reduces substantially the computational work and yields good agreement with the exact analysis. Rayleigh-wave dispersion on a laminated half-space for which exact dispersion equation cannot be obtained is also discussed by employing the continuum theory.