There is a kind of Cu-Ni sulfides deposits in the Sudbury region, Canada, the Shakespear deposit and Nairn deposit as a typical, which are controlled by the Nipissing mafic-ultramafic intrusive suite and unrelated to the Sudbury meteorite impact. The Nairn intrusion exposed I and II blocks, as dikes in NE toward, on the surface, which combined into a whole in deep. MagmaSdifferentiationSwas good in Nairn property,Swhich exhibits clear lithofacies belts from the bottom to the top. Massive-semi massive sulfides distributed in the lower of pyroxenite; disseminated sulfides distributed in the middle partSof norite-gabbro. Most of the rock units in the Nairn intrusion belong to the calc-alkaline series. According to the (Mg/) on (Mg+)/Si variation diagram, (Mg+Fe)/Ti-Si/Ti diagram, (Na2O+K2O) on SiO2 variation diagram, Al2O3 on SiO2 variation diagram, FMC diagram, the Nairn intrusion exhibited mafic-femic, low aluminum, weak-alkalic and low calcium (poor in calcium). Metallogenic mechanism in the Nairn area can be summarized into four magma evolution phases. Contamination of sulfur wall-rock and development of a double-diffusive interface (DDI) play an important role in the first and second phase for magmatic differentiation and isolating of sulfur-magma. Cu-Ni sulfides deposition was completed in the third and fourth phase.