Abstract: In this paper, the petrology, lithogeochemistry, and isotope chronology of Yemuqi granite closely associated with Early Paleozoic granite in the southern part of West Junggar, Xinjiang, were studied in detail. It is considered that the granite belongs to low potassium (tholeiitic) series. The rock geochemistry shows the characteristics of the intraplate close to island arc region. The authors obtained accurate age data of 539.7±2.6Ma by LA-ICP-MS zircon U-Pb dating of the monzonite granite. It is shown that the age of its formation was Early Cambrian. The intrusive rock is the oldest product of magmatic activity in the West Junggar area, which represents the geological record of the early stage of the splitting in the Early Paleoceanic Basin after the formation of the united continent of Nodingnia.