We report on the crystal-field energy levels calculation of Yb3+ ions in an AlN host using crystal-field theory. Cathodoluminescence spectra of AlN grown by molecular beam epitaxy on Si (0001) substrate and doped by implantation with ytterbium (Yb) ions were critically examined assuming that Yb3+ ions are involved in different sites. The comparison between the emission spectra of Yb3+ ions in the GaN and AlN indicates the presence of some similarities between the lattice locations of Yb3+ ions in these hosts. We demonstrate that assuming the existence of a substitutional YbAl(Ga) site and a VN-Yb complex defect in AlN (GaN) lattice, a good agreement between the measured and calculated energy values of Yb3+ ion transition lines can be obtained. Furthermore, we have investigated the Zeeman g|| and g⊥ parameters for the Yb3+ ion in an Al substitutional site as well as in the VN-Yb complex using the perturbation theory.