Abstract Structural changes in surface layers of CVD AlN films were studied by the reflection high-energy electron diffraction technique. Film thickness was varied from 0.2 to 20 μm. Single crystals of diamond, silicon carbide and also bilayered structures of natural diamond/CVD diamond films were used as substrates. On the (111) surfaces of natural diamond, (111) CVD diamond films and (00.1) 6H-SiC at AlN thickness up to 1 μm one can observe the epitaxial correspondence between the growing film and the substrate: (00.1) [11.0] AlN//(111) [110] C α or (00.1) [10.0] AlN//(00.1) [10.0] 6H-SiC. At larger film thickness the epitaxial growth was replaced gradually by the formation of one of axial textures for which the planes (00.1), (10.3) or (11.4) of wurtzite-like aluminum nitride were parallel to the substrate. During the epitaxial growth the twinning structures with the twinning planes of types (10.1) and (11.1) were observed.