The properties of the filter cake formed on the retentive membrane in dead-end ultrafiltration of bovine serum albumin (BSA) solutions were obtained by using a batchwise filter which had a sudden reduction in its filtration area. Moreover, the zeta potential of BSA was measured by the electrophoretic light scattering method in order to investigate the correlation with the properties of the protein cake. The experimental data clearly demonstrated that the plots of such properties of the filter cake as the average porosity epsilon(av) and the average specific filtration resistance alpha(av) against the absolute value of the zeta potential can almost be represented by a unique curve, respectively, irrespective of the sign of the zeta potential.