Objectives: Qimantage is located in the western part of the East Kunlun belt. The study of the Late Triassic igneous rocks in this area not only helps to understand of the Indosinian tectonic—magmatic evolution history of the East Kunlun orogenic belt, but also can provide constraints for the subduction and the closing time of the Paleo- Tethys Ocean. Methods: Detailed geological survey, LA- ICP- MS zircon U- Pb dating of monzogranite, whole rock geochemical and Nd—Pb isotopes analysis of igneous rocks in eastern Qimantage, East Kunlun orogenic belt. Results: The zircon U- Pb dating of the monzogranite in southern Ketinghaer is 219.8±0.5 Ma, combining previous ages it can be ascertained that the igneous rocks are the products of Late Triassic magmatic activities.The whole- rock geochemical analyses show that the Late Triassic igneous rocks in eastern Qimantage lie in high K calc- alkaline fields, the Aluminium saturation index show the metalumininous and weak peraluminous features,integrated with enrichments of LREE and LILE（Rb, Th, K, etc.）, depletions of Nb, Ta, P and Ti（HFSE）and obvious Eu negative anomaly, suggesting plate subduction- related geochemical affinities. Granites and rhyolites have similar Nd and Pb isotopic compositions.The εNd(t) of granites range from -4.66 to -4.53,the model age of depleted mantle range from 1363 Ma to 1375 Ma. The εNd(t) of rhyolite is -4.63, and the TDM2 is 1368 Ma. Projection points in n(143Nd)/n(144Nd)—n(206Pb)/n(204Pb) diagram and Pb isotopic compositions diagrams are located near the upper crust and EMII mantle regions. Conclusions: The Late Triassic granites and rhyolites in eastern Qimantage are closely related to their spatial distribution with similar formation time and similarity or consistency in major—trace elements and Nd—Pb isotopic compositions. Therefore, the authors believe that they are the products of homologous magma in the same period and tectonic environment. Combining achievements of predecessors with this study, it’s believed that the East Kunlun region was in the active continental margin arc environment during plate subduction, and the Paleo- Tethys Ocean was not completely closed in that period.