Studying on the new complied 1∶100 million magnetic and gravity map, writers find there are a group of northwest directional structures in Yanshiping-Chamdo area, eastern Tibet. In this paper, the authors clearly show the gravity and magnetic characteristics of the northwest directional structures and nearly east-west directional structures, and infer that the northwest directional structures could be split from the eastern Kunlun fault, Qilian-east Kunlun Mountains, while the previous view that the northwest directional structures connect with nearly east-west directional structures reflects the overlying epi-tectonic caused by India Plate shoving to the north after Jurassic. This discovery has very important significances for the understanding of the tectonic framework of Tibet.