Hydrothermal reduction of metal nitrates by ethylene glycol in the range of temperatures 180-270 degrees C with a view of obtaining nano-dimensional spinel structures has been studied. According to X-ray diffractometric measurements, samples that came as a result of nitrate reduction by ethylene-glycol at temperatures lower than 180 degrees C reveal largely phases of metal oxalates. At temperatures 220-270 degrees C, main products of the reaction are carbonates of appropriate metals. When calcinating samples which obtained as a result of the reduction of cobalt and manganese nitrate mixture at 900 degrees C, authors succeeded to get a spinel phase of (Co,Mn)(Co,Mn)(2)O-4. According to the X-ray-phase analysis, an average size of spinel phase particles made up 20.3 nm.