The Jiujiang-Ruichang area is an important ore concentrated district in the western section of the Cu-Fe-Au(S) mineralization belt of the Middle-Lower Reaches of the Yangtze River. Five poorly-studied granitic rocks at Dingjiashan, Yangjisha, Baoshan, Tongling, and Daliang, which are closely related to Cu-Au mineralization, were selected to conduct zircon LA-ICP-MS U-Pb dating and explore its geological significance. Zircon U-Pb dating results indicate that these granitic rocks formed in Late Jurassic to Early Cretaceous at (145.4±1.2) Ma, (144.8±1.3) Ma, (143.6±1.2) Ma, (141.2±1.3) Ma and (146.4±1.2) Ma, respectively, and may be the product of the Cretaceous magmatic activity. In combination to regional geological data, it is believed that the petrogenetic and metallogenic event in the Jiujiang-Ruichang ore concentrated district may occur in a transitional environment from the early orogeny stage of the paleo-Pacific Plate subduction to the subsequent back-arc extensional environment.