The LesserXing'an Range region, situated in the eastern segment of the Central Asian-Xingmeng Orogenic Belt, occupies a superimposed domain of three paleoplates: the Siberian, NorthChina,and Pacific Plates. As a significant molybdenum metallogenic belt in Northeast China, this area is characterized by 200~170 Ma Mo deposits. Recent studies on the Wudaogou Mo deposit in the northern margin of the Lesser Xing'an Range have, for the first time, identified Permian Mo mineralization through magmatic geochronology, establishing this deposit as a critical target for investigating Permian Mo metallogenesis, ore-forming settings, and host-rock petrology in the region. This work conducted detailed field and indoor geological investigations of the Wudaogou molybdenum deposit in the northern margin of the Lesser Xing'an Range. The basic characteristics of the deposit, including common hydrothermal alteration mineral assemblages, ore mineral assemblages, and mineralization types in the area were determined. Based on these findings, geochronological studies were carried out, yielding a Re-Os isotopic age of 170.4±1.3 Ma for molybdenite from the Wudaogou deposit, a zircon U-Pb age of 186.8±0.81Ma for coarse-grained alkali feldspar granite, and detrital ages of 371~690 Ma for siltstone, with the age lower limit constrained to the Late Devonian. This study reveals that: (1) The molybdenum mineralization in the deposit occurred during the Middle Jurassic (~170 Ma), rather than the Permian, which is consistent with the timing of major molybdenum deposits in the Lesser Xing'an Range.(2) The alkali feldspar granite in the mining area serves as the ore-hosting wall rock for the molybdenum orebodies, and its formation age predates the mineralization significantly. (3) The Wudaogou molybdenum deposit is a porphyry-type deposit, with a potential deep-seated porphyry mineralization system.(4) From the Paleozoic to the Early Mesozoic, the Wudaogou area developed a relatively continuous series of sedimentary rocks and intermediate-acidic magmatic rocks, which corresponded to the tectonic settings of subduction, collision, and post-orogenic extension related to the Nenjiang-Heihe Ocean.The Early-Middle Jurassic magmatic rocks and the associated Wudaogou molybdenum deposit were formed in a tectonic setting related to the subduction of the Paleo-Pacific Plate.