Abstract: Based on the 1∶50 000 aeromagnetic data in Xilinhot-Xiwuqi in 2009, aeromagnetic field feature of different structure units in this area were studied in this paper, combining with geology, remote sensing and gravity. The structural units were divided after comprehensive analysis. By comparison and analysis, this study find that the northern margin of North China Plate recognized from aeromagnetic is conformed to the structure from geological research, and the deep fault in northern Xilinhot should be indentified 10-20 km to north.