Abstract:We collected the deep Changjiang granite of different structure by drilling in the Mianhuakeng mining area, then tested its LA-ICP-MS zircon U-Pb dating, the main elements, trace elements, rare earth elements and Nd-Sr isotope. By the analysis and comparison, the fine-inequigrain biotite granite which existed in the contacts place with the Changjiang granite and the Youdong granite of shallow Indosinian, the deep mesograin biotite granite, and the deeper coarse-grained biotite granite also have the similar age, the same mineral composition and the similar geochemical characteristics, so that they should be the product of comagmatic evolution. In the Changjiang granite, the main elements' characteristics ware rich in Si, alkali, and potassium content were more than sodium content, the trace elements' characteristics were rich in large-ion elements, such as Rb, Th, the Ba, Sr, P, Ti element were apparent loss, and the Nb, Ta element were minor loss, the total amount of REE was lower and distinct diversification, the REE patterns showed that the light REE had been riched slightly, and Eu had been apparent loss, the value of (87Sr/86Sr)i was higher (average value 0.71066), the value of ε Nd (T) was lower (average value -10.1), the model age of Nd was old (average age 1.77Ga), and the component of source area was mainly sandy rock. In conclusion, the Changjiang granite was formation by melting crustal component in Paleoproterozoic Era with the extensional tectonic setting, which belongs to the crust-derived type granite.