Abstract：The Altyn Tagh fault as an important component part of the northern boundary of the Qinghai-Tibet Plateau has long attracted attention of the geoscience communities both at home and abroad. Based on an analysis of the regional gravitational field, the authors think that the southwestern part of the Altyn Tagh fault does not end at Gozha Co but is divided into two branches near the northeast of Gozha Co. One branch passes through Gozha Co and continues to extend in a WSW direction, and after passing Lungmu Co the branch enters Kashmir via the Kongka Pass. The other branch continues to extend toward the SW and ends in the Bangong Co-Nujiang junction near Bangong Co via west of Gyipug. The latter branch formed earlier than the former branch.