A silicone-coated thin film composite nanofiltration membrane composed of polyacrylonitrile/polyamide/poly(dimethylsiloxane) (PDMS) for the separation of the fatty acid dissolved in organic solvents was interfacially prepared by reacting trimesoyl chloride and PDMS with an aqueous phase containing piperazine (PIP) and m-phenylenediamine (MPD). Effects of the monomer blends ratio (PIP/MPD) and monomer concentration on membrane performance such as solvents (water, alcohols, ketones, and hexane) permeation and organic materials (poly(ethylene glycol) 200 and oleic acid) rejection rate were. investigated. Low concentration of the monomer and high content of the PDMS was needed for the high permeation of the solvents. The membrane surface property (hydrophilic or hydrophobic) studied by contact angle and zeta potential measurement was an important factor on the solvents permeation. The membranes showed high permeation of the hydrophobic solvent (hexane) and good rejection rate of the oleic acid dissolved in methanol and acetone.