Using laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), U-Pb dating and in-situ trace element analysis were performed on magmatic zircons from monzogranite porphyry and quartz porphyry in the Wunugetushan mining area, Inner Mongolia, to constrain the nature of the ore-forming magma and explore the main controlling factors of porphyry mineralization. The results show that the zircon U-Pb age of the monzogranite porphyry is 180.9±0.67 Ma, consistent with the previously reported molybdenite Re-Os age (≈180 Ma); the zircon U-Pb age of the quartz porphyry is 202.6±1.4 Ma, indicating that it is a pre-mineralization intrusion. Zircons from the syn-mineralization monzogranite porphyry exhibit significant positive Ce and Eu anomalies and high oxygen fugacity (ƒ_O2 is from −14.6 to −12.9, ΔFMQ is from +2.3 to +3.5), whereas zircons from the barren quartz porphyry show lower Ce and Eu anomalies and lower oxygen fugacity (ƒ_O2 is from −17.1 to −9.8, ΔFMQ is from −0.5 to +2.0). Both monzogranite porphyry and quartz porphyry zircons display high 10000×δEu/Y ratios and low Dy/Yb ratios, reflecting similar magmatic water contents. The zircon geochemical characteristics indicate that the primary magma of the ore-bearing monzogranite porphyry is characterized by high oxygen fugacity and water richness, whereas the primary magma of the barren quartz porphyry has relatively high water content but low oxygen fugacity, revealing the critical control of magmatic oxygen fugacity on porphyry mineralization potential. In the context of regional tectonic evolution, the Early Jurassic syn-mineralization period of the Wunugetushan deposit was likely influenced by the subduction of the Mongol-Okhotsk Ocean, with resulting partial melting generating the high oxygen fugacity, water-rich magma essential for mineralization.