A study of the treatment of printing and dyeing wastewater was carried out using the combined process of anoxic baffled reactor-biological contact oxidation. The results showed the pH ascended continuously and the oxidation-reduction potential dropped gradually from compartment 1-6 in ABR. When hydraulic retention time was 12 h, color removal efficiency was 92% and the color of effluent of ABR could satisfy the professional emission standard (grade-1) of textile and dyeing industry of China. The total COD removal efficiency of the combined process was 86.6% and the COD of effluent could satisfy the professional emission standard (grade-2) of textile and dyeing industry of China. (c) 2006 Elsevier Ltd. All rights reserved.