Two trenches LT1301 and SLT1204 were excavated in the Benge- Cunge section of the Litang left- lateral strike- slip active fault zone in the southeastern margin of the Qinghai- Tibet Plateau. Based on the detailed description of the paleoearthquake events revealed in the two trenches, 10 OSL and 13 14C dates, the ages of paleoearthquake events in the northern part of the Litang fault zone were determined. The results show that the at least four paleoearthquake events are recorded in these two trenches. Among them, the small- scale trench LT1301 only reveals one paleoearthquake, which may either be a historical earthquake in 1729 A. D. or a major earthquake between 950 a and 1. 0 ka, a distinction currently being not possible due to insufficient chronological data from key locations. The larger trench SLT1204 reveals four paleoearthquakes including the one in the trench LT1301. The oldest paleoearthquake event I occurred before 9. 9 ka. Events II, III and IV occurred between 1729 and 4. 8 ka BP with a recurrence interval of 1. 6 ka. The paleoearthquakes in the northern part of the Litang fault zone in the Western Sichuan indicate that the recurrence of large earthquakes in the fault has non- linear characteristics and does not conform to the characteristic earthquake model. The frequency of large earthquakes in the late Holocene increased significantly, indicating that the fault is in the stage of cluster activity.