Abstract: Recently, the U Pb isotope dating of single grain zircon from metavolcanic rock of Huangyuan Group yields an age of (910±6.7)Ma,and that from Xiangheer granite,which intrude into Huangyuan Group,yields an age of (917±12) Ma.In conbination with regional geological setting, it was considered that: (1) Huangyuan Group was formed not in Lower Proterozoic Subera, but in Middle Upper Proterozoic Subera, with upper age limit of about 900Ma; (2) Xiangheer granite was formed in Jinningian, rather than in Zhongtiaoian; and (3)both Huangyuan Group and the Jinningian granites which intrude into the former represent the crystalline basement of Jinningian cycle, not that of Zhongtiao cycle. The correction of the age of Huangyuan Group makes it necessary to further reexamine and study the previously established stratigraphic framework in east segment of Mid Qilian massif and its relationship with North China Plate and Yangtze Plate.