The Tanshuling molybdenum deposit is located in the Jiangnan Uplift zone along south part of the Jiangnan Fault. Its main lithology type is granodiorite. With the aim to constrain their magma and ore-forming ages and deposit genesis, combined zircon U-Pb and molybdenite Re-Os geochronology together with whole-rock major and trace element geochemistry have been carried out. The result suggest that the content of SiO₂is 64.5% ~ 66.8%, Al₂O₃ is 14.4% ~ 16.0%, K₂O is 3.92% ~ 4.86%, Na₂O is 2.90% ~3.91%, CaO is 1.56% ~ 2.8%, MgO is 1.24% ~ 1.53%, A/CNK value of 1.02 ~ 1.10, and A/NK value of 1.37 ~ 1.59. The characteristics of major elements show that the granites belong to metaaluminium to weak peraluminous high potassium calc-alkaline potassium series with I-type granite nature. The chondrite-normalized REE patterns are evidently right-declined, with relatively LREE enrichment and slight Eu negative anomalies. The molybdenite Re-Os age of the Tanshuling molybdenite is (133.09 ± 0.86) Ma, and the U-Pb dating of the Maolin granodiorite is (140.4 ± 0.62) Ma, (139.9 ± 0.66) Ma, (139.6 ± 0.63) Ma, all belong to the Early Cretaceous. Integrated chronological and geochemical characteristics show that the main magmatic activity of the Tanshuling molybdenum deposit belong to the Pacific tectonic system, and the alternation of extrusion and extensional has led to large-scale magmatic and mineralization in this area.