The energetic and electronic structures of precipitates on the Cu-rich side of Cu-Ni-Si alloys were investigated by using the first-principle calculations based on plane-wave pseudopotential method.The negative formation heats and the cohesive energies of these precipitates were estimated with electronic structure calculations, and their structural stability was also analyzed.The results show thatδ-Ni_2Si,γ-Ni_5Si_2 andβ-Ni_3Si precipitates all have great alloying ability and structural stability,which,after comparing their density of states (DOS),is found attributed to the pseudogap effect near the Fermi level(E_f)and strong hybridization between the Ni-3d and Si-3p states.Compared with the other two precipitates,theδ-Ni_2Si precipitate has the greatest structural stability,which is resulted from its lower DOS at E_f and the main bonding peaks slightly moving to the low energy region. The energetic and electronic structures of precipitates on the Cu-rich side of investigated Cu-Ni-Si alloys were used by the first-principle calculations based on plane-wave pseudopotential method. Negative heats and the cohesive energies of these precipitates were estimated with electronic structure calculations, and their structural stability was also analyzed. results show that δ-Ni_2Si, γ-Ni_5Si_2 and β-Ni_3Si precipitates all have great alloying ability and structural stability, which, after comparing their density of states (DOS), is found attributed to the pseudogap effect near the Fermi level (E_f) and strong hybridization between the Ni-3d and Si-3p states. Compared with the other two precipitates, the delta-Ni_2Si precipitate has the greatest structural stability, which is resulted resulted from its lower DOS at E_f and the main bonding peaks slightly moving to the low energy region.