Novel sea-urchinlike cadmium sulfide nanocrystallines with nanorod-based architecture are reported here. A rationally solvothermal method with hydrated cadmium chloride (CdCl(2)(.)2.5H(2)O) and thiourea ((NH2)(2)CS) in ethylenediamine solution has been successfully used to synthesize the sea-urchinlike cadmium sulfide nanocrystallines. The morphology, structure, and optical proper-ties of the final products have been investigated by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, selected area electron diffraction, and fluorescence spectrum. The probable formation mechanism of the sea-urchinlike cadmium sulfide nanocrystallines was discussed on the basis of the experimental results. (C) 2004 Elsevier B.V. All rights reserved.