The objective of the study was to investigate the influence of membrane material and membrane cut off on transport and separation properties of ultrafiltration membranes, as well as verification of the possibility of membrane techniques application for the recovery of bioactive components isolated from chicken eggs. Egg white solutions contain cysteine proteinase inhibitor - cystatin, which can be utilized, in the convenient state in liquid form, in some food and pharmaceutical industries. Commercial membranes made of polyethersulfone (PES) and regenerated cellulose (RC) were used in our experiments. Applied transmembrane pressure (TMP) varied from 0.05 to 0.30 MPa. Membrane filtration process led two step: first - microfiltration (MF) and second - ultrafiltration (UF). Microfiltration, using cross flow technique membranes made from polypropylene with 0.2 μm pores, was used as the first step of cystatin isolation from egg white (initial fractionation of egg white). Liquid products obtained by fractionation of egg white can be used as a partial feeding in the ultrafiltration installation. During ultrafiltration asymmetric membranes were used that were made of polyethersulfone and regenerated cellulose, with cut off of a molecular weight equal to 10, 30, 50 and 100 kDa. Polyethersulfone membrane with cut off 30 kDa was characterised by the highest yield of fractionated products with a high level of remaining specific biological activity. When membrane cut off point was increased specific activity of cystatin was lowered. Liquid fractions of egg white were characterised by high inhibitory activity of cystatin. The efficiency of cysteine proteinase inhibitor - cystatin - separation from egg white varied from 22 to 87%.