Yushishan Leptynite type Nb-Ta Deposit is a large Nb-Ta ore deposit discovered in western Central Qilian in recent years. However, the attribution of Nb-Ta ore bearing strata is unclear. On the basis of combing previous research results, through fine field research and regional comparison, this suit of strata has been redefined. It was disassembled from the Changcheng period Aoyougou Formation to establish a new lithostratigraphic unit, named the Neoproterozoic Yushishan Formation. The original sequence of Yusishan Formation was analyzed, and the formation process was also summarized. The research results not only provide new materials for stratigraphic contrast and research in the western section of the Central Qilian massif, but also provide a basis for prospecting and metallogenic research of Yusishan Leptynite type Nb-Ta deposit in the western section of the central Qilian massif.