The Pamir syntaxis is one of the typical continental collision orogeny. The Dugeli alkali-rich porphyries on the eastern margin of Pamir is of great significance to reveal the Cenozoic tectonic evolution in this area. The rock mass intrudes into silty slate of the Early Permian and is mainly composed of syenite porphyry and quartz syenite porphyry. The LA-ICP-MS zircon U-Pb dating of the Dugeli porphyry yielded an age of 10.76±0.09 Ma, revealing that the rocks formed in the Middle Miocene. Geochemical analysis indicates that the Dugeli porphyry belongs to the metaluminous to weakly peraluminous A-type granite with features of alkali-rich, high-potassium. Trace elements show high enrichment of LILE, such as Rb, Sr, and Ba, and depletion of HFSE, such as Nb, Ta and Ti. The total REE content in the porphyry is high, and the REE chondrite- normalized distribution pattern shows distinct right leaning, light REE enrichment, with no obvious negative Eu anomaly. These features suggest that the magma source is the thickened mafic lower crust, which underwent metasomatism of ancient subducted oceanic slab fluids and was injected by enrichment mantle material. It is concluded that the Dugeli alkali-rich porphyry was formed in extensional tectonic setting during the post-collision stage and records the response to the India-Eurasia collision orogeny in the tectonic transition zone of northwest of the Qinghai-Tibet Plateau.