Abstract: The Tertiary in the Kumkol basin,Xinjiang,may be divided into the Oligocene Huatiaoshan Formation,middle lower Miocene Hongshiliang Formation,middle Miocene Fengchenkou Formation and Pliocene Jiantuliang Formation.It is lithologially represented a sequence of terrigenous coarse clastic sediments.Analysis indicates that the Kumkol basin is an independent basin that began its depositional history in the Eogene but was to some extent connected with the Qaidam basin.Both may be well correlated in biotic appearance.The Tertiary sediments of the basin were derived from the Kunlun Mountains to its south and the Qimantag Mountains to its north.