The western Tarim Basin is a convergent zone of the Southwestern Tianshan Mountains and the Pamir, and there have been big debates about its exact boundary. However, in the Mayikake Basin, the boundaries of two tectonic systems are very clear: the north-vergent Pamir Front Thrust is the leading edge of the Pamir, and south-vergent thrust at south limb of the Wulagen anticline, which was discovered in recent field study, is the south margin of the Southwestern Tianshan. Regional correlation indicates the high terrace is the same surface as the T2 located at north limb of the Mushi anticline with the age of ~16 ka, which indicates the average shortening rate of south limb of the anticline in Late Quaternary is ~4.5 mm/a.