In this work, the nanocomposites, carbon nanotubes (CNTs) coated with nanosized uninterrupted SnO2, were prepared controllably by a facile solvothermal method. The obtained nanocomposites have a thin overlayer which is made of nanoparticles with a diameter of similar to 3 nm. The products were characterized by X-ray diffraction and transmission electron microscopy. The obtained SnO2/CNTs have an excellent electrocatalytic oxidation performance for the X-3B, a kind of dye. The parameters affecting the electrocatalytic activity were investigated in details. The excellent catalytic property of the SnO2/CNT electrodes can be explained as follows: (1) high specific surface area gives more active sites for X-3B oxidation; (2) the formation of thin, uniform, and uninterrupted coverage of SnO2 nanoparticles on CNTs raises the potential of oxygen evolution and the current efficiency; and (3) the CNTs increase the conductivity of the electrodes, which results in the increase of the current efficiency. (C) 2008 Elsevier B. V. All rights reserved.