An in situ vesicle-template-interface reaction route was introduced to prepare self-encapsulated CdS microspheres, which can be obtained by heating an ethanol solution after ultrasonic irradiation in the presence of Cd(NO3)(2), CS2, and sodium dodecyl sulfate. The products were characterized by various techniques of XRD, TEM, UV-Vis spectrum, and PL spectrum. (C) 2004 Elsevier Inc. All rights reserved.