Abstract: There are large Cenozoic thrusting nappe structure in the Si Nongduo area, Xie Tongmen, Tibet. Dipping direction of the thrust plane is about 200° and dip angle is about 15~ 25°. The upper wall is made up of Carboniferous Anji limestone and dolomitic limestone, forming towering steep cliff on the nappe front. The lower wall is mainly comprised of volcanic rocks from nianbo formation of Eocene. The fault zone is approximately 60km in length and 2~3km in width. According to the relative position of klippe, the upper nappe is estimated to slip is about 15km toward northeast. It is supposed that the Indian plate subducting northward strongly pressed the Gangdise area, which caused the formation of this thrusting nappe structure.