The nanocrystalline nickel powder were prepared by highenergy ball milling and DC arc plasma evaporation method respectively, subsequently the two kinds of powder were consolidated into bulk nanocrystalline nickel by cold compaction and sintering. The structure and morphology change of the bulk nanocrystalline Nickel were researched. The particles were observed by TEM and the selected area electron diffraction patterns of nickel powders were shown; then XRD and Archimedes method were carried out to determine grain size and porosity of the two specimens respectively and contrastive analysis were performed. The results of investigation showed that, for both specimens, grain size and relative density increased, but lattice strain decreased with the increasing sintering temperature. Moreover, it was found that grain size and relative density growth rate of milling sample were higher than those that prepared by plasma evaporation method.