A new continuous flow three-dimensional electrode-packed bed photocatalytic reactor was developed to investigate the feasibility of an electrochemically assisted photocatalytic process in the degradation of reactive brilliant orange K-R dye in 0.5 mmol l(-1) NaCl solution. It was found that the dye could be degraded more efficiently by this photoelectrochemical process than the degradation obtained by photocatalytic oxidation or by electrochemical oxidation alone, in terms of both decolorization and TOC removal. Various parameters, such as applied cell voltage, initial concentration of chloride ion and the dye, pH value and airflow were the major factors affecting the oxidation rate of the dye. It is interesting to find that an obvious enhancement effect rather than a scavenging effect on the photoelectrocatalytic degradation of the dye in a salt solution was obtained in the new-designed photoelectrocatalytic reactor. (C) 2003 Elsevier B.V. All rights reserved.