Based on an investigation into 1:200 000 regional gravity field in northwest Hebei, this paper deals with characteristics of the regional gravity field and, according to inference and interpretation of regional fault structures, puts forward some new understanding concerning the main structures. The three NW-trending faults, namely, Kangbao-Chicheng-Miyun fault (F₁₁), Zhangbei-Zhangjiakou-Huailai-Changping fault (F₄₇) and Wanquanyulingou-Zhuoludaolazui fault (F₄₈), were recognized on the basis of gravitational and magnetic information. The EW-trending Kangbao-Guyuan, Chongli-Chicheng and Tanzhen-Miyun faults, NE-trending Zhangbei-Guyuan and Huailai-Shanghuangqi faults, and NW-trending Lanchengzi-Longmensuo, Zhangbei-Shahe and Yulingou-Nanliushui faults constitute deep fractural framework of this area.