Abstract:By using finite-difference forward modeling method,we analyse the three-component seismograms of some dual-layer models (EDA-isotropy,PTL-isotropy and isotropy-isotropy models)。The extensive dilatancy anisotropy resulting from fractures can be seen in three-component data. First model brings three-component synthetic seismograms which show obvious shear wave splitting and clear P-SH wave in Y component. In the second model case,shear wave splitting exists also,P-SV wave can be found in X component,and Y component only shows single shear wave without P-SH wave. Three-component seismograms of the third model have no shear wave splitting,and only pure shear wave can be observed in Y component.The article offers X and Y component data which were collected from coal seam area;and it is proved that P-SH wave in Y component results from coal seam fractures.