We explore a new concept for controlling the anticoking performance over nickel-based catalysts for methane conversion into synthesis gas at 1173 K. When CaTiO3 type oxide exhibiting ionic and electronic mixed conduction introduced by the partial substitution of titanium(IV) site by iron(III) ion is used as a support material, coke formation over the catalyst during methane conversion with air or carbon dioxide is strongly dependent on the iron(III) ion content. From the relationship between the amount of carbon deposited on the catalyst and the mixed conduction in the support oxide, it is found that the self-migration of lattice oxygen inside the support regulating the balance between the oxide ionic and electronic conductivities plays an important role to prevent accumulation of deposited carbon over the catalysts.