PVC hollow fibers were prepared using dry/wet phase inversion method. The effects of PVC concentration and extrusion pressure on the morphology and separation performances of the PVC membranes were investigated. PVC membranes were characterized in terms of SEM, pore size distribution, and porosity, while UF experiments were conducted by using pure water flux and PVP rejection. It was found that the hollow fiber is composed of four layers and a symmetric structure is formed with increasing PVC concentration. The effective pores show a sharp distribution pattern at 0.113 mu m with 99% pore size frequency for hollow fibers prepared from 15 wt% PVC and 0.75 bar as extrusion pressure. At 14 wt% PVC and 0.3 bar as extrusion pressure, the effective pores show a distribution with maximum pore size at 0.106 mu m and a pore size frequency above 99%. Pure water flux decreased from 380 to 119 (l/m2h bar) and from 315 to 158 (l/m2h bar) and PVP rejection increased from 3 to 85% and from 21 to 63% include the increase in PVC concentration using 0.75 and 0.3 bar extrusion pressure, respectively. PVC concentration affected the tensile strength at break, elongation at break and Young's modulus of PVC membranes.