Ordered mesoporous manganese oxide (m-MnOx) which consists of catalytic active MnO2 and Mn2O3 phases has been successfully synthesized by a simple template casting method. The as-prepared m-MnOx sample exhibited excellent catalytic activity on the degradation of tetraethylated rhodamine (RhB) dye. The degradation efficiency was found greatly influenced by the catalyst concentration, the reaction temperature and the pH value of the reaction system. The decrease of chemical oxygen demand (COD) value was also observed along with the decolorization indicating the mineralization of the dye. (c) 2010 Elsevier B.V. All rights reserved.