Two technological processes of synthesis of nanopowders containing Al2O3, AlN, and AlON have been investigated. It has been established that AlN nanoparticles formed on the base of ablation products (Al and N2) during laser irradiation of AlN targets are coated with AlON films of different composition and have a complex surface defective structure. In composite powders obtained by carbothermal reduction of Al2O3, along with AlN and AlON, initial oxide Al2O3 is present, which indicates the incompleteness of the process.