NOVELTY - Preparing an aqueous emulsion of a midblock sulfonated styrenic block copolymer comprising at least two non-sulfonated polymer end-blocks and at least one sulfonated block, comprises: (a) providing a cement of the midblock sulfonated styrenic block copolymer in an apolar solvent; (b) mixing the cement of step (a) with a co-solvent to form a mixture; (c) emulsifying the mixture of step (b), in the absence of a surfactant, with water to produce an emulsion; and (d) removing the hydrocarbon solvent and optionally the co-solvent from the emulsion to produce the aqueous emulsion.    USE - The process is useful for preparing an aqueous emulsion of midblock sulfonated styrenic block copolymer (claimed), which is useful for preparation of moisture permeable membrane and coating which are useful in fuel cells, all separation equipment and in clothing, energy recovery ventilation and water purification.    ADVANTAGE - The process: provides stable emulsion of the midblock sulfonated styrenic block copolymer having relatively small particle diameters; and is economically feasible.    DETAILED DESCRIPTION - Preparing an aqueous emulsion of a midblock sulfonated styrenic block copolymer comprising at least two non-sulfonated polymer end-blocks A and at least one sulfonated block B, comprises: (a) providing a cement of the midblock sulfonated styrenic block copolymer in an apolar solvent, where the apolar solvent is a hydrocarbon compound with a boiling point of 49-99 degrees C or mixture of such compounds; (b) mixing the cement of step (a) with a co-solvent to form a mixture; (c) emulsifying the mixture of step (b), in the absence of a surfactant, with water to produce an emulsion; and (d) removing the hydrocarbon solvent and optionally the co-solvent from the emulsion to produce the aqueous emulsion. The apolar solvent comprises Hansen polarity parameter ( delta p) smaller than 2 (expressed in square root of MPa), and the co-solvent is a polar aprotic solvent or polar protic solvent with the Hansen polarity parameter of 2.8-15, and a Hansen hydrogen bonding parameter ( delta h) of 4-27 (expressed in square root of MPa). An INDEPENDENT CLAIM is also included for aqueous emulsion of the midblock sulfonated styrenic block copolymer comprising at least two non-sulfonated polymer end-blocks and at least one sulfonated block, having a solids content of 10-30 (preferably 10-15) mass% calculated on the mass of the emulsion, where the average particle size of the particles of the midblock sulfonated styrenic block copolymer as determined by laser diffraction spectroscopy is at most 2 mu m, containing up to 1500 ppm calculated on the mass of the emulsion of a co-solvent, where the co-solvent is a polar aprotic solvent or polar protic solvent with a Hansen polarity parameter of 2.8-15, preferably 5-12 and a Hansen hydrogen bonding parameter of 4-27 (calculated in square root of MPa).