ZnS Nanostructures, including nanoparticles and nanospheres, were synthesized through solvothermal process. The size and crystallinity of the ZnS nanostructures were easily controlled by the precursor source and the solvents. The photoluminescence (PL) in the range of 400-650 nm has been observed and the broad band is peaked at about 525 nm. The PL intensity reduced greatly with increasing the nanoparticle size of the as-prepared samples and the ratio of zinc and sulfur sources in the preparation process. Spectral examinations and analyses reveal that the 525 nm emission peak indeed originates from the electronic states determined by the zinc vacancies.