The paper deals with the taxonomy of two species of the subgenus Trachycarabus Géhin, 1876 of the genus Carabus Linnaeus, 1758, occurring in the Altay Mountains in the Xinjiang Uygur Autonomous Region of China: C. (T.) mandibularis Fischer von Waldheim, 1828 and C. (T.) sibiricus Fischer von Waldheim, 1820. A new subspecies, C. (T.) mandibularis abakkereiorum subsp. nov. is described from the Kran River Valley near Altay City. A new synonym is proposed: C. (T.) sibiricus obliteratus Fischer von Waldheim, 1828 = C. (T.) s. pseudobliteratus Korell et Kleinfeld, 1982, syn. nov. A key to the Trachycarabus species currently known from Xinjiang is given.