Poly(vinyl butyral) (PVB)/surfactant with high molecular weight (Pluronic F127) blend hollow fiber membranes were prepared via thermally induced phase separation (TIPS) from PVB/Pluronic F127/diluent (PEG200) system. The phase diagram of PVB/PEG200 system was obtained and the addition of Pluronic F127 to this system led to the decrease of the cloud point. In order to know the kinetic property in the membrane preparation process, a light scattering experiment was carried out in cooling process of the PVB solution. The result indicated that the initial interphase periodic distance formed from the phase separation of PVB/Pluronic F127/PEG200 system was smaller than that of PVB/PEG200 system and its growth rate was lower in the former system. The properties of the hollow fiber membranes such as water permeability, particle rejection and hydrophilicity were investigated. The air gap distance in the membrane preparation condition highly influenced the water permeability. (C) 2007 Elsevier B.V. All rights reserved.