According to the selection principle of grain refiners and calculation of planar disregistries, CeO2 and TiB2 particles were selected as the grain refiners of pure nickel. The change of grain size and refining effects of different refiners under the same melting conditions were investigated. The results show that the grain size of pure nickel gradually reduces with increasing the amount of grain refiners. And with increasing the amount of CeO2 up to 0.7 wt%, the grain size of pure nickel decreases from 323.0 to 53.5 lm. In addition, when the amount of TiB2is0.7 wt%, the grain size is reduced to 41.3 lm. According to the selection principle of grain refiners and calculation of planar disregistries, CeO2 and TiB2 particles were selected as the grain refiners of pure nickel. The change of grain size and refining effects of different refiners under the same melting conditions were investigated. The results show that the grain size of pure nickel gradually reduces with increasing the amount of grain refiners. And with increasing the amount of CeO2 up to 0.7 wt%, the grain size of pure nickel decreases from 323.0 to 53.5 lm. TiB2is 0.7 wt%, the grain size is reduced to 41.3 lm.