Abstract: This work deals with the structure of crust and upper mantle as revealed by an experimental study along the Kangzhuang—Dachang ( 康庄—大厂) profile near Peking, China by observing converted seismic waves of earthquakes. Layered and faulted block structures are indicated. By analyzing and comparing the superficial and deeper structural features of the region, it can be found that a nearly NWW-SBB oriented strong horizontal stress field has been in action within the crust and thus given rise to the up- and downwarping structural units of the region.Hypocentral distributions of earthquakes in this region may be that west of the Gaoliying(高丽营) fault, most of the earthquake foci are located on the top and bottom surfaces of the so-called granitic layer, while east of the Gaoliying fault, they are mostly on the fault belt itself. (Fig. 1).