Accurately constraining the age and source of primary U mineralization is commonly difficult as diverse U minerals are affected by alpha-recoils and subjected to overprints of multi-stage fluids. Titanite has a good potential in revealing rock-forming and metallogenic information, and widely occurs in magmatic, metamorphic, and hydrothermal U deposits. However, the textural and chemical characteristics of titanite from these U deposits are poorly documented and little is known about the relationship between titanite and U mineralization. At the western margin of the Yangtze Block, a series of U occurrences and uraninite-predominant ores are hosted in the leucocratic dykes, ranging from fine-grained (albitised) monzogranite to pegmatitic quartz vein. The genesis of U mineralization remains unclear largely because of the uncertainties as to the timing of mineralization and the origin of metals.Here, we present comprehensive U-Pb and Sm-Nd isotopic data, and major and trace element compositions for metamorphic (Ttn-I) and magmatic/hydrothermal (Ttn-II) titanites from the leucocratic dykes and/or amphibolitic wall rocks. Ttn-I is in direct contact with metamorphic hornblende and plagioclase or occurs as xenoliths hosted in the leucocratic dykes, and is thus inferred to result from amphibolite facies metamorphism. Chemically, Ttn-I is characterized by low Fe/Al ratios, LREE-depleted patterns and weakly negative to positive Eu anomalies. By contrast, magmatic/hydrothermal Ttn-II crystals intergrown with uraninite in the leucocratic dykes generally display flatter REE patterns, more negative Eu anomalies, higher Fe/Al ratios, and U, Nb, REE and Y contents, which could be applied as an indicator for U exploration. LA-ICP-MS U-Pb dating on Ttn-I yielded ages of-860 Ma for amphibolite facies metamorphism. Instead, U-Pb dating on syn-ore Ttn-II yiel-ded ages of-786-779 Ma for U mineralization, which is coeval with the emplacement of leucocratic dykes. Uraninite and intergrown Ttn-II have uniform, negative epsilon Nd(t) values (-5.7 to-15.5), indicating the initial melts were predominantly sourced from the old crustal materials (TDM2 =-1.9-2.7 Ga). Considering the oc-currences as dykes, feldspar-quartz-dominant lithologies, and wide textural and compositional variations of leucocratic dykes, we infer that low-degree partial melting of U-rich protolith is the main factor controlling U concentration in the melt. Variable REE patterns and ThO2 contents in different uraninite types seem to imply there have been multi-stage U mineralization.