This paper introduced an approach that used an industrial filter-cloth material instead of the conventional MF/UF membrane to build a membrane bioreactor (MBR) for wastewater treatment. The formation and filtration capacity of the dynamic membrane and the performance of the dynamic MBR for treating municipal wastewater were investigated. The results of the batch tests showed that the dynamic membrane could be formed on the filter-cloth surface quickly and developed steadily. It played an essential role to reject particulate matter. Higher sludge concentration could contribute to the formation of dynamic membrane, but lead to elevated SS concentration in the effluent and lower permeation flux. For treating municipal wastewater sequentially, in the permeate turbidity was less than 9 NTU and SS was zero at the most operation time under the MLSS concentration of less than 6000 mg L-1. At hydraulic retention time (HRT) of 6.9 h and temperatures of 9-13 degrees C, the total COD and ammonia removal ranged 72-89% and 66-94%, respectively. The total resistance of the dynamic membrane was lower than that of the MF/UF membrane 2-3 numeral classes. Cake layer resistance was the major resistance. (C) 2006 Elsevier B.V. All rights reserved.