In this study, composite membrane was prepared by chemical polymerization of pyrrole on the surface of the ultrafiltration membrane using ferric ions. The performance of the prepared membrane was characterized by filtration of bovine serum albumin (BSA) solution through the membrane in various conditions. For conductive membrane, higher rejection was obtained compared with non-conductive membrane. This effect can be attributed to the conductivity of the membrane. The negatively charged membrane surface acts as a barrier against BSA. Moreover, the protein is pushed back due to the electrostatic effect. This results in higher rejection. For conductive membrane, lower fluxes were obtained for the same condition. It can be attributed to the partial blocking of the membrane pores with polypyrrole. The pH effects were complex. Around isoelectric point, the protein particles lose their charge and produce larger particles, which settle on the membrane surface resulting in lower flux and higher rejection. At the pHs far from the isoelectric point, rejection was decreased.