Abstract: Elastic waves excited by a plane source with an arbitrary shape on the surface of a multilayered medium have been studied. At first, 2D elastic wavefield in a multilayered medium is extended to 3D space, and the propagation of elastic wave is studied in the frequency domain. Then, the excitation and propagation of the Rayleigh and Love waves are analyzed further. It is found that the propagation velocity of the Rayleigh and Love waves does not depend on the propagation azimuth θ in the plane parallel to the free surface of the multilayered medium while the displacement amplitude of the Rayleigh and Love waves is strongly dependent on the azimuth θ. Finally, the elastic fields excited by a rectangle source, strip source with infinite length, and circular disk source are studied, and theoretical representation and numerical results of the displacement directivity distribution both of the Rayleigh and Love waves are obtained.