Neutron stars, stellar remnants of core-collapse supernova explosion, were first discovered as radio pulsars.  The salient feature of the neutron star lies in its compactness, which gives us an opportunity of "observing" matter at extremely high density.  In this talk, I would like to discuss condensed matter aspects of neutron stars, which include a peculiar lattice structure of nuclei, neutron superfluidity, and liquid crystalline structures of a nuclear matter liquid-gas mixture.