Small and uniform nano-TiO2 particles were obtained by sol-emulsion-gel method. Optimum preparation conditions include the surfactant concentration at the critical micelle concentration (CMC) and the pH value at 8-9. The calcinations could improve the crystallization of TiO, powders and accelerated the phase transformation from amorphous phase to anatase or rutile. Seen from the TEM, the spherical and uniform nano-TiO2 particles were obtained as calcined at 500 degrees C, and the gradual shape change of the particles in the process of calcination was noticed: Formed sphere -> Rod -> Sphere -> Distorted sphere. (c) 2006 Elsevier B.V. All rights reserved.