The hydrothermal reductive decomposition of Cu²⁺, Co²⁺ and Al³⁺ nitrates in the temperature range of 220–350⁰С in the presence of polyols (ethylene glycol and glycerol) was investigated. It has been established, that depending on the synthesis conditions the forming of highly dispersed oxide systems of Cu–Co–Al and/or with admixture of metallic copper are possible. The products of reaction by physicochemical methods: XRF, SEM, spectroscopy in the IR and UV ranges are characterized. A correlation between the reaction conditions and the physical and chemical properties of the nanopowders was established. A possible scheme for the flow of reaction is proposed.