CdS nanorods with the diameter of 30, 60, 140 and 650 nm were, respectively, synthesized by hydrothermal method. The products were characterized by XRD, TEM and XPS technique. It was found that the chemical control of CdS nanorods diameter can be realized by simply changing the sulfide source in hydrothermal process. The mechanism for chemical control of US nanorods diameter was discussed. (C) 2003 Published by Elsevier B.V.