Abstract: The Al₂O₃/Ni-Co composites with different additives were fabricated by pulse current electrodeposition, the microstructures of Al₂O₃/Ni-Co composites were studied by TEM and EDS. The effects of additives on the smoothness, microhardness, plasticity at room temperature and at high temperature were compared. SEM was employed to examine the microstructures of the deformed samples. The hardness, fracture strength, elongation at room temperature and at superplastic temperature of the Al₂O₃/Ni-Co composite reach HV469, 1150 MPa, 7% and 417% respectively, when the saccharin was used as additive.