Abstract: Linxi Formation is mainly consist of clastic rocks. New research from Linxi detritial zircon by the LA-ICP-MS U-Pb dating showed that the 50 zircons analyses gave two age populations: 256±2～322±3Ma with the peak age at 279Ma and 357±7～497±4 Ma with peak age at 441 Ma. In addition, three analyses yielded ages of 797±6 Ma, 1413±38 Ma, and 1661±24 Ma. Detrital zircon age from this study indicated that 256±2 Ma limited the depositional age of the Lixin Formation and 441±3 Ma represented the main source area (from NE China blocks) age. 797±6 Ma, 1413±38 Ma, and 1661±24 Ma represented the basement rocks in the NE China blocks. New date from this study suggest that Linxi Formation belongs to NE China blocks. Therefore the suture zone between the Siberia and North China is situated in the southern of Linxi Formation, which locates along the Xar Moron suture, and the timing for the final collision should be later than Late Permian, probably at Early Triassic.