The Ag/CdS core/shell nanoparticles are synthesized by a facile method. The synthesis steps are simple and easy to be manipulated. The core/shell nanostructures are characterized by the transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-vis spectrometry techniques. Compared with bare Ag and CdS nanoparticles, the optical absorption of Ag/CdS composite nanostructures is greatly enhanced in a wide range of visible light. It can also be demonstrated in the simulations based on DDA method. The enhanced absorption of light is mainly due to the localized surface plasmon resonance (LSPR) effect excited on silver core. The optical response of such core/shell nanostructures is extended to longer wavelengths. (C) 2013 Elsevier B.V. All rights reserved.