Abstract: To reconstruct the Late Paleozoic tectonic evolution process of Xingmeng Orogenic Belt, Moguqin pluton in the southern segment of Xing'an Block was selected as the research object. The authors in this paper conducted zircon U-Pb dating and analyzed major, trace and rare earth element geochemical characteristics of the pluton, with a detailed investigation of its petrogenetic type and tectonic setting. The results showed that it was primarily composed of medium-grained alkali feldspar granite, with an emplacement age of (303.5±2.2) Ma, and it contained enclaves of syenite and diorite. The trace and rare earth element distribution curves of alkali feldspar granite and syenite enclaves were consistent, showing characteristics of large ion lithophile element Rb, Th, K enrichment, and Sr, P, Ti depletion. The total rare earth content was medium to high, showing Eu negative anomaly. The genetic type of rock mass belonged to peraluminous (weakly peraluminous) A-type granite, while the diorite enclaves belongs to moderately differentiated intermediate rocks. The formation of Moguqin pluton was closely related to the evolution of Paleo-Asian Ocean, representing the magmatic activity of the extensional environment after the closing of Paleo-Asian Ocean basin. This research results are indicative of constraining the regional tectonic framework and could provide references for defining the closure timing of the Paleo-Asian Ocean basin.