Abstract: Large quantities of granites are developed in the southern margin of Altay orogenic belt. The previous studies have focused on the formation age and structural setting of the granites from the eastern section of Altay orogenic belt, but the research its western section is still limited.Muzitawu Plutons are located in Muzitawu area of Western Friendship Peak, Burqin County, Altay, Xinjiang, which are mainly consist of biotite granite, porphyritic biotitesyenogranite and muscovite syenogranite.In these plutons, the pegmatite veins are very developed, with rare metal mineralization. The LA-ICP-MS zircon U-Pb method was used to study the chronology of porphyritic biotitesyenogranite, and the zircon ²⁰⁶Pb/²³⁸U weighted average age of the plutons is (198.3±3.8)Ma (MSWD=2.0), indicating that these plutons were formed in early Jurassic. This age is basically in line with the metallogenic epoch of pegmatite vein-type rare metals in the eastern section of Altay orogenic belt, which provides a chronological restriction for the study on the mineralization epoch of rare metal-muscovite-gemstone relating to pegmatite in this area.