Abstract Super-Kamiokande (SK) currently continues data taking as the fourth phase of the experiment (SK-IV). Because of improvements in the water circulation system, the background in the low energy region was reduced and solar neutrino signals are observed even at 3.5–4.0 MeV kinetic energy. Consequently, the SK solar neutrino measurement provided better determination of oscillation parameters ( θ 12 and Δ m 21 2 ) and checks on the matter effects of oscillations. SK also has been searching for galactic supernovae. The SK-I to III limit on the flux of supernova relic neutrinos (SRN) has reached near the predictions of several models. In order to detect the SRN signal, tagging neutrons is necessary. For this purpose, a prototype gadolinium-loaded water Cherenkov detector has been constructed.