To investigate mechanical behaviors and deformation mechanisms of nanocrystalline materials, bulk nanocrystalline Ni samples were prepared by plasma evaporation method combined with hot pressure sintering in this paper. The compressive mechanical properties of the bulk samples were tested under different quasi-static strain rates at room temperature and the evolution of microstructure of bulk sample before and after compression was studied. The bulk samples show a good combination of strength and ductility during the compressive testing. Meanwhile, grain size of the compressed sample decreases compared with that of sintered sample, while the microstrain of the grain increases after compression. Based on experimental results, it is can be inferred that both grain boundary dislocation glide and grain boundary sliding mechanism are main operating deformation mechanisms for the bulk NC Ni samples.