The pollution of fresh surface water and the increasing demands with regard to health and the quality of our water magnify the availability problem. water purification, therefore, will play a key role in the coming decades in the world-wide growth in health and prosperity. there is a need for robust, selective and economical purification techniques. in addition, recycling of wastewater is going to determine a large part of the success of these new technologies. membrane filtration is one of the most promising technologies that has emerged in the past decade covering all these requirements. if membrane filtration was to become one of the leading water treatment technologies for large applications, energy consumption had to be cut. one of such process is ultrafiltration process. ultrafiltration is characteristically used for the removal of collides and macromolecules from aqueous solution. in this process rejection is determined mainly by shape and size of solute relative to the pore size of the membrane and since it is pressure driven membrane separation process, transport of solvent is directly proportional to the applied pressure. the major limitation of ultrafiltration process is membrane fouling which is resulted by increased solute concentration at the surface of membrane either by the adsorption of macromolecules to the internal pore of the membrane or accumulation of solute molecules on surface of membrane and subsequently reduces the life span of membrane and declines the flux. hydrophobicity is a major drawback of this material. as a result of hydrophobicity these membranes have a tendency to be fouled. polysulfone polymer is largely used for the fabrication of ultrafiltration membranes. it is a better polymeric material among various polymers such as polyamide, cellulose acetate, polycarbonate. it has wide temperature and ph limits, physicochemical stability, fairly good resistance to chlorine. plasticizers are important additives which can enhance the performance of polymers. branched polyester blends based plasticizer could have maintained their mechanical and material properties throughout the aging. we can increase the hydrophilicity of the modified membranes by the addition of amino alcohol plasticizer i.e aap (which were synthesized by the reaction of iah and peg). we use iah (isatoic anhydrides) because it’s plasticizer can be used as an additive in membrane for improving the hydrophilicity of membrane and we must use lower molecular weight peg (polyethylene glycol) to make the membrane more hydrophilic than compared to higher molecular weight peg.