A BP layer was grown on a (0 0 0 1)-GaN by atmospheric-pressure metalorganic VPE procedure. The BP layer grew epitaxially on the GaN with relationship: (0 0 0 1), < a-axes >-GaN/(1 1 1), < 1 1 0 >-BP. On the surface of (1 1 1)-BP layer, crystallites disposed with double positioning configuration were found. The presence of crystallite disposed with the double positioning indicated that the BP layer grew up on the GaN with the manner of "degenerated epitaxy". In the (1 1 1)-BP layer grown through "degenerated epitaxy- manner, crystalline imperfections, such as { 1 1 1 }-twins were involved. (c) 2004 Published by Elsevier B.V.