The waves scattered by underground heterogeneities are studied by numerical simulation; and effects of the scattered waves on the surface wave velocity are analyzed. The results indicate that the location of a heterogeneity can not be effectively detected from variation of the phase velocity with the receiver position. Because energy of the scattered waves is small in the surface wave field

the scattered waves are not easily distinguished. When the source is taken as the center

and a group of receivers are symmetrically set along a measuring line

the scattered wave field can be obtained by comparing particle responses on two sides. The scattered Rayleigh waves dominate the scattered wave field

the locations of underground heterogeneities can be predicted by variation of traveling time of the scattered Rayleigh waves with the distance between the receiver and the source. Finally

the detection schemes are proposed.