Hualong, is located in the South Lajishan, has developed many small basic-ultrabasic intrusions, simultaneously, is a great important Ni-Cu metallogenic belt in South Qilian Mountains, and formed Yulonggou, Lashuixia, Yaqu small scale magmatic Ni-Cu sulfide deposits that related closely with these small intrusions. Ore isotope study revealed that the Ni-Cu deposits had formed from crystallization and differentiation of the original magma, suffered from crustal contamination, and the participation of Si-rich material. Together with regional tectonic evolution and mineralization reorganization, it suggests that the formation of rock and ore in Hualong were related closely to geological environment on subduction.