Abstract: The effects of the composition of the polymer, additives，the solvent evaporation time,and the gelation media on the membrane structures/morphology which are prepared by phaseinversion process will he represented in the paper. The structure of membranes become thick shinlayer from thin skin layer with increase in the composition of the polymer. The appropriate structure and permeability of membranes can he prepared by using additives in the casting solution.The macropore structure will he suppressed by adding solvent in the gelation media. The structure of top surface become the loose structure with increase in the solvent evaporation time, and it will he a certain degree after a specific value of the solvent evaporation time.The effects of the composition of the polymer，additives，the solvent evaporation time，and the gelation media on the membrane structures/morphology which are prepared by phase inversion process.

Key words: polysulfone membrane, polymer concentration, additive;the solvent evaporation time;the gelation media