We developed an innovative cBN honing stone (cBN-NI1 honing stone) using novel nano-polycrystalline cBN abrasive grains (cBN-NI1 grains) synthesized under conditions of ultra-high pressure and temperature. The cBN-NI1 grains have a tri-modal nano-polycrystalline structure consisting of coarse crystal grains, fine crystal grains, and lamellar crystal grains, with both hardness and fracture strength exceeding those of conventional representative polycrystalline cBN grains (cBN-W5 grains). Based on honing experiments using these cBN grains, we clarified that the cBN-NI1 honing stone had superior wear resistance to the cBN-W5 honing stone, and as a result the grinding ratio was more than seven times higher when using the cBN-NI1 honing stone than the cBN-W5 honing stone. Furthermore, it was confirmed that both the finished surface roughness and the shape accuracy when using the cBN-NI1 honing stone were better and more stable than those when using the cBN-W5 honing stone.