Abstract Extracellular polymeric substances (EPSs) in activated sludge suspensions are the key substances leading to the membrane fouling. In order to understand the effect of EPSs on the membrane fouling, the actual EPSs solution extracted from activated sludge suspensions was used as the feed solution to conduct dead-end microfiltration experiment under different pressures by using different membranes. The flux (J), fouling resistances (R_m, R_p, R_c and R_total ) and the available membrane area (A/A₀ ) were used to describe the membrane fouling. The results showed that with the increase of pressure, J and R_total increased. R_p firstly increased and then kept constant, R_c always increased and became the dominant resistance. A/A₀ decreased from 1 to a constant. R_c plays a key role on R_total for different membranes under the same pressure. The sequence of the steady available membrane area (A _steady/A₀ ) for different pressures was: 63.0% (0.05MPa)> 56.5% (0.08MPa)> 53.6% (0.10MPa), and that for different membranes was: 80.1% (0.2μm PES) > 79.9% (0.1μm PES) > 78.4% (0.1μm PAN) > 53.6% (0.1μm PVDF).