In this report the spontaneous polymerization of vinyl monomer using the superconductor YBa₂ Cu₃O_7-δ was studied. It is known that superconducting characters of this material is influenced by conditions of oxidation in the synthetic process. Although the superconductivity transition temperature, T_c of fully oxidized YBa₂Cu₃O₇ (Y7) is about 90K, this material is transferred to a semiconductor YBa₂Cu₃O₆ (Y6) with tetragonal structure upon reduction at high temperature and under low oxygen pressure. The Y7 could be dispersed in the polymerization of methyl methacrylate (MMA), but not for the Y6. Thus the PMMA with the powder of Y7 was composed. The process of the polymerization is the free radical chain reaction. The composite resin itself is an insulator, but the T_c is observed by the measurement of alternating current susceptibility. The T_c of the superconductor in the matrix resin is almost similar to that of assintered. The superconductor in the composite resin has water proofness and thermostability.