The nano-scale indium tin oxide (ITO) particles are synthezed by liquid phase co-precipitation method under given conditions with solution of indium chloride, tin chloride and ammonia. The absolute ethyl alcohol or deionized water was used as solvent and the dodecylamine or hexadecylamine surfactant as a dispersant in the reaction system. The sample powder was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and high resolution electron microscopy (HRTEM). Based on the transmission electron micrograph， the influences of the two different solvents and the two different dispersants on the nanoparticle size and dispersion were studied respectively. The results shown that the ITO particles are finely crystallized body centered cubic structure. The particle size has distributed in 30nm to 90nm.