Orthorhombic single-crystalline cerium carbonate hydroxide (CeCO3OH) with one-dimensional (1D) microstructures has been successfully synthesized by a facile sonochemical reaction between cerous nitrate and urea. These 1D microstructures were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FE-SEM). The assynthesized CeCO3OH has uniform lengths and good dispersion. Synthetic parameters, such as the concentration of reagents, were found to have close relationship with the morphologies and sizes of the final products. The ultrasound-induced oriented attachment growth mechanism has been proposed for the possible formation mechanism of sample. Room-temperature photoluminescence of CeCO3OH samples with different morphologies has also been investigated. (C) 2009 Elsevier Ltd. All rights reserved.