The Gaoshanhe Formation developed in the southwestern margin of the North China Craton (NCC) is one of the most important Mesoproterozoic stratigraphic units. However, its depositional age and regional correlation have been debated for a long time. In this study, the LA- ICP- MS zircon U- Pb dating results show that the tuff samples from the lower Gaoshanhe Formation of the Maxia section in Huating, Gansu produces U- Pb ages of 1759±17 Ma. Combined with the regional data and previous study results, the depositional internal for the Gaoshanhe Formation can be limited roughly in to the period from 1770~1600 Ma, and further prove that the Xiong’er Group were erupted mainly from 1800~1770 Ma. With this data, the depositional age of the Ganshanhe Formation in the southwestern margin of the NCC can be calibrated accurately as the first time. It not only confirms the stratigraphic age, but also has great significance for the division and correlation of the Mesoproterozoic strata in the whole southwestern margin of the NCC and furtherly studying the micropalaeontology in the southwestern margin of the NCC.