Abstract Two programs for next-generation spallation neutron sources in Japan are described. One is the so-called KENS-II project as a part of the Japan Hadron Project (JHP), which includes the construction of a new H −-linac (1 GeV, 400 μA) and a compressor/stretcher ring (1 GeV, 200μA). When a higher beam intensity from the H −-ion source becomes available, KENS-II can be upgraded to 1 MW. On the other hand, at the Japan Atomic Energy Research Institute, the construction of a high-power proton linac (1.5 GeV, 10 μA) is being planned for nuclear transmutation. By accelerating an H −-beam simultaneously with protons and constructing a compressor ring, we can expect a 1–3 MW pulsed source. As another option, by utilizing a fraction of the direct proton pulses from the linac (about 10 pulses out of 100), we can expect an intense pulsed cold-neutron source (time-averaged cold neutron flux: 1/2 to 1/3 ILL, peak flux: 20 ILL). Extensive discussions for a possible collaboration between the two programs have started.