A new shape nanosized HgSe was synthesized in the presence of ethylene glycol, which was found to act as both reducing agent and be favorable to the formation of tapered HgSe nanorods. It was also observed that the ultrasonic power played an important role for the shape of the final products. X-ray powder diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy were employed to characterize the HgSe nanorods. Other polyol solvents, such as diethylene glycol and polyethylene glycol 200, were also used to the preparation of HgSe nanoparticles. The possible mechanism of the formation of taper shaped HgSe nanorods was discussed. (C) 2003 Elsevier B.V. All rights reserved.