High performance ion exchange chromatography using aqueous solvents is presented for the separation of proteins. Diethylaminoethyl(DEAE) resin for the anion exchange column and sulfopropyl(SP) resin for the cation exchange column were utilized. Proteins, having a molecular weight of 10000 - 190000 daltons and an isoelectric point of 3.9-10.7, were separated within 60 min by sodium chloride linear gradient elution. The protein was eluted according to its isoelectric point. These columns are capable of separating proteins with the biological activity in high speed, high resolution, large capacity and considerably high recovery.