Аннотация:The device characteristics of thin films based on the AlN-GaN system have a large dependence on the substrate materials, because heteroepitaxial film becomes dominated by extended defects arising, first of all, from the substrate/film lattice mismatch. This paper results an attempt to develop structural criteria to guide the search for more effective substrates for the deposition of GaN films following our experience concerned with crystallochemical aspects in crystal growth of oxide materials. Over fifty various inorganic crystals as well as some of their solid solutions have been considered in search for a replacement substrate. Among them, the main attention was paid to candidates from the viewpoint of phase stability, easy of growth and other physico-chemical properties. The epitaxial relations were examined for some crystallographic orientations of the Ga-nitride and substrates like Al2O3, ZnO MgO, ZrO2, HfO2, MgAl2O4, ZnAl2O4, ZnGa2O4, TiZn2O4, YAlO3, LaAlO3, LaGaO3, LaGaO3, NdGaO3, KTaO3, SrTiO3, Si, SiC.