The Luming molybdenum deposit is located in the middle-south segment of the Cuihongshan-Ergu ore-forming subbelt along the Xiao Hinggan Mountains-Zhangguangcai Mountain polymetallic belt. Mo mineralization occurs in granitic pluton and monzonitic granite, and wall rock alterations are characterized by zoning of magmatic hydrothermal alterations. Petrogeochemical studies show that the granite porphyry and the monzonitic granite have the same magmatic source and belong to “A”-type granite, formed by magmatic invasion in the background of stretching geotectonic environment. SHRIMP U-Pb dating yielded the age (201.1±3.90) Ma and (176.2±4.3) Ma for monzonitic granite and (182.3±4.0) Ma for granite porphyry, suggesting that the Luming Mo deposit was formed between 182 and 176 Ma, belonging to Early Yanshanisn period.