The major and trace elements and Sr-Nd isotopes of the Huangshandong mafic-ultramafic intrusion in the Huangshan-Jingerquan magmatic Cu-Ni mineralization belt are reported to constrain its formation and the regional tectonic evolution. Three stages of magma intrusion have been identified. The first magmatic emplacement formed the main portion of the intrusion. The hornblende gabbro comprises the upper and lower parts and olivine gabbro presents in the middle part, whereas diorite occurs along the margins of the intrusion. The resultant of the second stage emplacement forms gabbronorite dykes in the western and northwestern of the intrusion. Iherzolite, lies in the lower part and regarded as the main host rock for the Cu-Ni ores, represents the products of the last magma intrusion. Except the TiO2 contents of the olivine gabbro and hornblende gabbro, the major elements of the Huangshandong intrusive rocks plot among the mineral composition of olivine, orthopyroxene, clinopyroxene and plagioclase, indicating these are dominant rock-forming minerals. Compared with mafic-ultramafic intrusions of the Permian Tarim large igneous province, the Huangshandong intrusion is characterized by lower contents of incompatible elements (La, Ba, Th, U), higher εΝd (t) (7.32~8.29) and more depleted in Nb, Ta and Ti. In addition, the Huangshandong intrusion displays relatively low Th/U and Nb/U (1.13~2.98 and 2.53~7.02, respectively) and high La/Nb and Ba/Nb (1.15~4.19 and 37.7~79.82, respectively). These features are similar to the subduction-related extrusive and intrusive rocks, indicating that Huangshandong intrusion was formed by partial melting of a metasomatic mantle source modified by the subducted slab-derived melt/fluid. The partial melting of such mantle source was triggered by asthenosphere upwelling.