A hydrothermal process has been developed to prepare CU2O particles by reducing the Cu(II)-citrate complex with NaH2PO2. A series of shape evolutions of Cu2O particles from the species such as cubic crystals to eight-pod particles have been synthesized via a kinetically controlled process by adjusting pH of the solution. The products were characterized by transmission electron microscopy (TEM), scanning electron microscope (SEM), X-ray power diffraction (XRD). Possible crystal growth processes have been proposed on the basis of the experimental results. (c) 2007 Elsevier B.V. All rights reserved.