Abstract: LA-ICP-MS zircon U-Pb dating for the two-mica syenogranite of Talsayi pluton in the southern margin of the northern Altaid orogenic belt yielded a ²⁰⁶Pb/²³⁸U age of 235±2 Ma(MSWD=0.46), which interpreted as product of the early Late-Triassic magmatic event.Whole-rock geochemical data show that two-mica syenogranite and two-mica monzogranite of the Talsayi pluton are characterized by high silicon and alkali, low titanium and magnesium, as well as large Rittmann Index and Aluminum Saturation Index(A/CNK)values.The lines of evidence indicate that the granitic rocks are classified into high potassium calc-alkaline peraluminous granitic series.In addition, the syenogranite and monzogranite are relatively enriched in light rare earth elements(LREE), as well as trace elements of Rb and Th, but depleted in high field-strength elements of Nb, Ta, Yb and Y, in addition, the granitic rocks show low values of magnesium and contents of Cr and Ni, and moderate values of CaO/Na₂O and low values of Al₂O₃/TiO₂.These suggest that the Talsayi pluton in the southern margin of the northern Altaid orogenic belt were formed in the syn-collision tectonic environment.Combination with the previous studies, it is proposed that the transition of tectonic regime of the Altaid orogenic belt show spatiotemporal difference with characteristic of trending from east and central to north direction during Triassic era.