Abstract: Two reverse fault groups, one of them is NWW-trending and the other is in NW-trending, develop in Yanqi basin. There are two styles of fault combination on plane, one of which shapes as Chinese word "入",the other shape as an echelon.The tectonic deformations on plane are characterized by zonal dividing in NS direction and block dividing in EW direction. Styles of fault combination on profile are imbricate, back thrust, ramp thrust and flower structural form. NWW-trending and NW-trending structural belts develop in the basin. NWW-trending structural belts are caused by left-lateral compresso-shear force, while NW-trending structural belts are caused by right-lateral compresso-shear force. Compresso-shear force plays a leading role in tectonic deformation. Mechanism of tectonic deformation is compresso-shear force from SSW-direction.