Ab initio SCF-MO calculations are carried out for intercalation compound Cu-hBN by using molecular cluster model. Geometry optimization of hBN layer is calculated at the 6-31G* basis set level, while single point calculation at the same basis set level is carried out for Cu-hBN. From the calculated interlayer distances, Mulliken populations, orbital interactions, atomic net charges and frontier orbital energy levels, the electronic structure and stability of Cu-hBN are discussed. It is confirmed by vibration analysis that this intercalation compound is merely a metastable structure. The densification mechanism of hBN ceramics by copper is also discussed. (C) 2002 Elsevier Science B.V. All rights reserved.