In this paper, nickel nanopowder was prepared by liquid phase reduction method, where nickel acetate and hydrazine hydrate was used as nickel source and reducing agent, respectively. The resulting Ni nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM). The results showed that nickel acetate can be effectively reduced by hydrazine hydrate. The as-prepared nickel nanoparticles are in spherical shape, with size ranging from 100 to 200nm and good dispersion. By changing the reaction conditions, the morphology and size of nickel particles can be controlled. The synthesized nickel nanopowders meet the general requirements of nickel powder that would be used for conductive paste, which can be prepared for nickel-based conductive paste. This method has some advantages such as inexpensive, non-pollution to environment; it can be used for industry.