The roles played by surfactant, Span-80, in the formation of polysulfone (PSf) hollow fiber membranes were studied. The obtained PSf hollow fiber membranes were utilized in the vapor permeation of aqueous ethanol solution. The effects of spinning conditions such as air gap, spinning solution composition, and the composition of bore liquid on the formation of hollow fiber membranes were studied. The effects of feed composition, and feeding temperature on the vapor permeation performances were also investigated. The hollow fiber membrane prepared from 23 wt.% PSf containing 15 wt.% Span-80 at an air gap of 30 cm gave the best vapor permeation performance, a water/ethanol separation factor of 54.3 and a permeation rate of 75.6 g/m(2) h.