An electroless deposition technique is used to synthesize nanocrystalline Ni-B coating in strengthening the surface of pure copper. The microstructure and some properties of Ni-B coating are studied. It is practicable to coat a uniform and continuous nanocrystalline Ni-B hardening layer on copper surface by this technique, Ni2B and Ni3B are formed in the Ni-B coated layer during heat treatment, and the average grain size of nanocrystalline Ni-B coating is about 42-65 nm and properties of the prepared copper alloys are also improved. (c) 2006 Elsevier B.V. All rights reserved.