This paper presents the measurements of Pb isotope compositions of apatite, magnetite and pyrite in the Washan and Dongshan iron deposits in the Ning-Wu (Nanjing-Wuhu) area. The 232Th- 208Pb isochron age of apatite is 124 Ma, which is consistent with the ages of gabbroic dioritic porphyrite and albitite, suggesting that the ore-formation age is similar to that of the rocks. The initial magma of Mesozoic igneous rocks in the study area was mixed with 3.3 Ga old rock series in the deep continent. Ore lead of the deposits mainly came from magma of ore-bearing matrices. The ore-forming fluid has a specially high ratio of Th/U, indicating obvious enrichment of Th compared with U, which probably reflects that halogen complex is the main carrier for the migration of mineral substance in the fluid.