Koseki, T. JACoW Geneva, Switzerland Accelerator-based neutrino oscillation experiments have played an important role in the confirmation of the neutrino oscillation and in precision measurements of the oscillation parameters. Two cutting-edge experiments, T2K and NOvA, open a door for the CP violation study in the neutrino sector using intense proton beams of several hundred kW from the Main Ring of J-PARC and the Main Injector of Fermilab, respectively. In this talk, a review of high intensity proton accelerator facilities for the next-generation accelerator-based neutrino oscillation experiments is presented. In these facilities, superconducting rf is a key technology to realize MW and multi-MW proton beams.