A new method for the preparation of liposomes in one step using supercritical carbon dioxide without any toxic organic solvents had developed. This method allowed to obtain aqueous d ispersions of liposomes through emulsion formation by introduction of a given amount of water into a homogeneous mixture of supercritical carbon dioxide/L-a-Dipalmitoylphosphatidylcholine/ethanol and subsequent pressure reduction. TEM observations using the freeze-replica method on the obtained vesicles revealed most of them are large unilamellar liposomes (LUV) with diameters 0.1-1.2mm. Trapping efficiency of the liposomes indicated more than five imes higher trapping efficiency for the water-soluble solute than that of multilamellar vesicles (MLV) prepared by the Bangham method.