A detailed study on the solution polyeondensation of dipotassium salt of 4，4’-dihydroxydiphenylsulfone and 4，4’-diehlorodiphenylsulfone is performed．Sulfolane is chosen as polycondensation medin while mixed xylene is used for azeotropic removal of water during the formation of dipotassium salt．Effects of polycondensation tempera-ture。time and solid content have been studied．Influences of monomer ratio and ratio of alkali to bisphenol-S during salt formation on product molecular weight have been discussed and a method is proposed for reducing the amplitude of fluctuation of pro-duct molecular weight by addition of potassium carbonate besides potassium hydroxide during salt formation．Factors influencing heat stability of polyarylsulfone at process-ing temperatures are discussed．and method for quality control of the after treatmentst ep has been recommended．The chief properties of PAS obtaJned are also listed．