Preparation of the sulfonated polysulfone and the performance of sulfonated polysulfone membrane were researched.Sulfonic groups are introduced onto PSF by sulfonation reaction.The influences of amount of sulfonating agent,reaction time and temperature on the degree of sulfonation of the obtained SPSF were studied.The result shows that the performance of SPSF/ PSF blend membrane used 32.8%degrees of SPSF was optimum.