Nearly monodisperse antimony pentoxide with a mean diameter of 2 nm and polydispersity of 0.047 was prepared through a simple method based on reflux oxidization system. By adjusting the synthetic parameters (kinds of stabilizing agents, size and purity of of original Sb2O3 etc.), the controllable synthesis of ultrafine Sb2O5 can be easily achieved. Detailed investigations about the effects of experimental parameters on the colloid stability and size distribution of the final products were carried out. The particles were characterized using vafious experimental techniques such as transmission electron microscopy (TEM), X-ray diffraction (XRD) and particle size distributions. (c) 2007 Elsevier B.V. All rights reserved.