Micellar-enhanced ultrafiltration (MEUF) can be used to separate effectively the low-molecular-weight organic compounds from the aqueous stream. Surfactant is added to the aqueous stream containing low-molecular-weight organic compounds below 300 Daltons such as alcohol, benzene and phenol. Above the critical micelle concentration (CMC), most organic compounds easily solubilize in the micelles formed by surfactant. CMC's of the ionic surfactants were determined effectively and accurately by the measurement of ion conductivity and surface tension. Micelle phase which contains most of the solute is rejected since the pore diameter of the membrane is smaller than that of the micelle. Therefore, most of the surfactant and low-molecular-weight organic compounds remain in the retentate solution while permeate solution which contains a very small amount of organic solute and surfactant is discarded or recycled. In the present study, ultrafiltration was carried out with the hollow-fiber membrane module for the continuous separation of phenol. The primary thrust of this research lies in the systematic assessment of the role of interaction between the micelle phase and the memebrane surface in the presence of a mean flow; and an investigation of the effects of concentration polarization, microstructure of the micelle, molecular-weight-cut-off (MWCO) of the membrane, solubilization capacity, CMC of the surfactant, operation conditions such as time, pressure difference and concentration of feed solution on the rejection efficienty of the organic compounds.