The influence of rare earth elements nature on Mn02 electrode electrochemical modification process in solutions of their salts in aprolic organic solvents was investigated. It was proved that periodicity of properties inherent in the lanthanides lakes place in the products of their interactions with MnO, and it is connected with characteristics of their structure. It was shown that the choice of metal as a modifying agent may be decisive in choosing the conditions of synthesis of cathode materials.