A brief review of our recent research on preparation and characterization of oxide nanoparticles and their derivatives by hydrothermal growth is presented. A series of Ga2O3 , ZnO, and TiO2 nanoparticles, as well derivative nanomaterials including GaN nanowires and ZnO/TiO2 nanocompostes have been prepared. Ga2O3 and ZnO nanopowders have been produced using metal nitrate hydrates as precursors, while Titanium isopropoxide was used for preparation of TiO2 nanopowders. GaN nanowires have been produced by nitridation of Ga2O3 nanomaterials. The produced nanomaterials have been characterized scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis and Fourier transform infrared (FTIR) spectroscopy. Ga2O3 nanoparticles doped with Eu3+ ions have been characterized by photoluminescence spectroscopy in order to assess their prospects in developing nanophosphors materials.