  Searches for astronomical neutrino sources and weakly interactive massive
particles (WIMPs) using the Super-Kamiokande detector have been performed. We
select the neutrino-induced upward muon events for the first 4 years, which is
already the world largest data sample, and look for statistically significant
excesses compared to the atmospheric neutrino background. No excess has been
found so far. Limits of upward muon flux from various potential sources are
obtained. Also limits of upward muon flux due to annihilations of WIMPs in the
Earth core, the Sun and the Galactic center are obtained as a function of WIMP
masses.
