Bowknot-like CeO2 bundles crystals were successfully prepared from a single precursor via a thermal decomposition route. The precursor was synthesized by a hydrothermal reaction using Ce(NO3)(3) center dot A 6H(2)O with CO(NH2)(2) at 150 A degrees C in a water-glycerol complex solution. Glycerol plays a very important role for the formation of precursor bowknot-like structures. The morphology of the precursor was maintained during the heating process. The optical absorption spectrum indicates that the CeO2 dendrites have a direct band gap of 3.42 eV, which is mostly larger than values of bulk powders due to the quantum size effect. The electrochemical characters of the CeO2 bundles structures are studied by their investigation of cyclic voltammetry (CV). It was found that the CeO2 bundles can greatly improve the electron transfer ability.