By electrophysical methods it has been shown that potassium-containing compounds, which, mixed with aromatic amines, exhibit synergism in the inhibition of high-temperature oxidation of esters, form reversed micelles when dissolved in pentaerythritol esters. The critical concentration of micelle formation is in good agreement with the content of potassium salt that is most effective in high-temperature oxidation. A scheme of the participation of reversed micelles in the inhibition of high-temperature oxidation of lubricants is proposed.