Abstract: The study of Triassic granitic rocks in East Kunlun mainly focuses on the large granite batholith with the characteristics of I−type granite, while the study of a small amount of peraluminous granite is less. The LA−ICP−MS zircon U−Pb dating of The Zhanhongshan rhyolite porphyry shows that the crystallization age of the Zhanhongshan rhyolite porphyry is 245±1 Ma. The Zhanhongshan rhyolite porphyry is characterized by high silica (SiO₂=74.50%～75.59%), rich Na (Na₂O=4.04%～4.06%), high Na₂O/K₂O ratio (1.26～1.76), and aluminum saturation index (A/CNK=1.07～1.14), which indicate weak peraluminous medium potassium and high potassium calc−alkaline series. The rocks is characterized by low REE content with obvious fractionation of LREE and HREE, slight negative and positive Eu anomalies (δEu=0.80～1.06), also enrichment of LILE and depletion of HFSE. They have enriched Hf isotopic compositions with εHf (t) isotope values of −4.7～+0.9. It is concluded that the peraluminous Zhanhongshan rhyolite porphyry has the characteristics of I−type granite, which is the result of the underplating of the subducted oceanic crust through mantle−derived magma and partial melting with the addition of foreign fluid, and has arc magmatic geochemical characteristics. Combined with the previous data, the study shows that the East Kunlun area was in the subduction stage of the Paleo−Tethys ocean in the Early Triassic.