To prepare a high flux and antifouling filtration membrane used for submerged membrane bioreactors, non-woven fabric (NWF) was modified by coating chitosan (CS) on both internal and outer surface. Chemical structural and morphological changes were characterized. The changes of surface free energy were monitored by dynamic contact angle, which showed an increase after modification. The CS/NWF composite membranes were found to be with high flux, high effluent quality and excellent antifouling property. The results of fouling resistance distribution indicated that irreversible fouling resistance was decreased by coating CS. Especially, there were fewer gel layers existing on the outer surface. The adsorption of EPS on the NWF membrane internal surface decreased after being coated with CS. Modification improved filtration performance, and made fouling less troublesome and membrane regeneration efficient. (C) 2010 Elsevier Ltd. All rights reserved.