Modified cellulose acetate (CA) ultrafiltration membranes were prepared using Pluronic F127 block copolymer as both pore-forming agent and surface modification agent. The watercontent of modified CA membranes increased with an increase of Pluronic F127 content in the casting solutions. The scanning electron microscopy (SEM) photographs showed that the modified CA membranes had thinner top layer and bigger pore volume in the porous sub-layer compared to the CA control membrane. The decrease of static water contact angle with an increase in Pluronic F1 27 content indicated an increase of surface hydrophilicity. The results of Fourier transform infrared spectrometer (FT-IR) analysis confirmed that most of Pluronic F127 has been leached out from the modified CA membranes. The ultrafiltration experiments revealed that the addition of Pluronic Fl 27 influenced the permeation performance of the membranes, all the modified CA membranes exhibited higher water flux and higher bovine serum albumin (BSA) rejection ratios than those of the CA control membrane. (C) 2007 Elsevier B.V. All rights reserved.