The combustion synthesis of the YBa2Cu3Oz–xceramic superconductor was achieved from CuBaO2and Y2O3mixtures, using both self-propagating high-temperature synthesis (SHS) and thermal explosion modes. Particular attention was paid to establishing the mechanism of formation of the YBa2Cu3O3–2product. Previous studies included effects of BaO2and Cu particle sizes, along with quenching of reacting pellets. It was shown that the mixture of reactants undergoes a complex sequence of reactions before eventually forming the final product. In the present work, the effect of the Y2O3particle size has been investigated. The initiation of YBa2Cu3O7–xformation has also been studied by providing a portion of the copper as either Cu2O or CuO. It is shown that the oxidation of Cu to form Cu2O is a necessary step for the reaction to become self-sustaining, but that excessive oxidation to Cu2O inhibits the reaction, leading to partially reacted pellets.