The formation of metallic nanooxides via detonation reaction was investigated with respect to the presence of an energetic precursor, such as the metallic nitrate and the degree of confinement of the explosive charge. The detonation products were characterized by scanning electron microscopy. Nano-metallic oxides with diameters from 10 to 50 nm and a variety of morphologies were found. Carbon particles in the oxides, the grey detonation soot, indicate a catalytic growth mechanism in a sense. The detonation synthesis technique is one of the methods of producing nano-metallic oxides. The oxides produced by this cheap method affirmed the validity of detonation synthesis of nano-size powders. The paper is concerned with the fabrication of alumina. The microstructure, distributions of the Al2O3 were determined. The results show that the nano-metallic oxides produced by detonation of nitrate explosives are between 20 to 50 nm. This investigation also promotes the design of commercial explosives and the development of detonation theory on a microscale.