Using the inorganic zinc salt and S powder as zinc and sulfur sources separately, micrometer-sized ZnS hollow spheres were synthesized. XRD pattern indicates that as-prepared sample is cubic ZnS. The effects of reaction time, reation temperature and different zinc sources on the morphologies were studied. SEM images show that the micro-spheres with diameters ranging from 200to 300nm are self-assembled by ultra-fine particles. Flower-like ZnO nanocrystals built up by nano-flakes are successfully synthesized in the presence of surfactant CTMAB. The feasibility of the reaction is discussed thermodynamically and the formation mechanism of spherical and flower-like ZnS is proposed.