Abstract: The Mazongshan arc is an important component of the Beishan orogenic belt, and its widely distributed Early Paleozoic intrusive rocks are of great significance for studying the early Paleozoic tectonic and magmatic evolution in the Beishan area. This study conducted petrological, geochemical, and zircon U-Pb geochronological studies on the Pochengshan granodiorite in the Mazongshan arc. The LA-ICP MS zircon U-Pb age is 451.4 ± 1.9 Ma (MSWD=1.2), indicating an early Late Ordovician period. The rock has high SiO₂ (62.25-69.6%), Al₂O₃ (14.34-14.68%), Na₂O+K₂O (6.07-6.44%), and is a high potassium calcium alkaline, quasi aluminous granite. The distribution curve of rare earth elements shows a gentle right tilt, with light rare earth elements slightly enriched, enriched in large ion lithophilic elements (such as Rb, Ba, Th, K), and depleted in high field strength elements (such as Nb, Ta, Sr, P, Ti). The geochemical characteristics indicate that the Pochengshan granodiorite is a product of partial melting of the newly formed lower crust under the influence of mantle derived magma intrusion in a subduction environment, and the magma source area has been subjected to the alteration of subduction zone fluids and the addition of mantle derived components. It is a response to the northward subduction of the early Late Ordovician in the ancient ocean represented by the Hongliuhe Niujuanzi Xichangjing ophiolite.