Nanosized copper ferrites were prepared by thermal method from the corresponding hydroxide carbonate precursors varying the temperature of synthesis. The phase composition of the obtained materials was characterized by XRD, Mössbauer spectroscopy, DSC and TPR analysis. Their catalytic properties were tested in total oxidation of toluene and methanol decomposition to CO and hydrogen. The relation between the synthesis parameters, phase composition of the samples and their transformation under the oxidation or reduction reaction medium was investigated in turns to understand the catalytic behavior of the obtained materials.