Based on a large number of highly- precise dating data obtained for the Tongling district, this study carried out the supplementary LA- ICP- MS zircon U- Pb dating for 11 samples from small intrusive rocks in Qiziken, Yaoshan and Hehuatang, etc. which are poorly studied. The ages obtained in this study are distributed mainly between 147 Ma and 131 Ma. Systematic study of rock- and ore- forming ages suggests that this district is a large ore cluster area resulted from the Yanshanian intracontinental instantaneous large scale mineralization. The ore- forming intrusive rocks in the study area are mainly composed of granodiorite, quartz diorite (monzobiorite), and pyroxene diorite (monzobiorite), and rock- forming ages range from 148 Ma to 137 Ma, from 152 Ma to 130 Ma, and from 150 Ma to 134 Ma, respectively, with the rock- forming age mainly from 152 Ma to 130 Ma. The Re- Os isotopic ages of molybdenite from the important deposits in the Tongling area mainly range from 141 Ma to 137 Ma. The difference between the rock- and ore- forming ages was less than 10 Ma, and the difference of ore- forming ages of adjacent ore- field was less than 20 Ma, with ore- forming ages gradually becoming young from east to west. The three episodic large scale mineralization in the Tongling ore cluster area occurring within the short interval of ages (141~137 Ma) is rare in the global intracontinental magmatic mineralization.