Abstract⎯In recent years, the opening of the rings of aromatic and naphthene hydrocarbons has been con sidered as a way way of improving the quality of motor fuels. In gasolines, the opening of monocyclic com pounds like di and trialkylcyclohexanes allows the synthesis of high octane components (C 7 -C 10 iso paraf fins). In diesel fuels containing considerable amounts of bi and trinuclear polycyclic compounds such as derivatives of naphthalene (decaline), phenanthrene, and indane, this allows the synthesis of monocyclic compounds and alkanes, thus leading to a reduction in the freezing temperature of the fuel and, when obtain ing predominantly linear alkanes, to an increase in the cetane number. In this work, we conduct a brief anal ysis of accumulated data on the opening of cyclic compounds on oxide and zeolite supported catalysts.