ZnSe nanoparticles were synthesized through a vapor-phase reaction of zinc and selenium and deposited as random aggregates on a water-cooled copper collector. X-ray diffraction (XRD) and transmission electron microscopy (TEM) demonstrate that the as-grown nanoparticles are polycrystalline ZnSe nanoparticles. Their diameters can be controlled through the deposition temperature. Raman spectra of nanoparticles with different diameter-size distribution and bulk material were measured at various excitation laser power with 632.8 and 532 nm laser. The phonon confinement mode was considered, and three-phonon process were used to explain the Raman spectra variation. The temperature effect of Raman scattering on microcrystalline was more obvious when excited with 532 run laser than 632.8 nm laser, and small-size particles show a stronger temperature effect than large-size particles. (C) 2004 Elsevier B.V. All rights reserved.