Abstract: 2H-WS2 nanoplates with thickness of 30 nm were obtained by a mechanical activation method using WO3 and sulfur as raw materials. The effects of temperature, preserving time and annealing conditions on products were characterized by XRD, SEM and TEM. The reaction process and reaction mechanism were analyzed. Results show that sulfurization was finished in only one step, and ball-milling played a crucial role in this reaction. A typical self-assembly step was realized in annealing process, and was controlled by the annealing temperature. In order to get homogeneous hexagonal WS2 nanoplates, ball-milling before annealing was necessary, which could prevent nanoplates from growing up.