Abstract: In order to obtain high activity and purity of antihypertensive peptides, the method of ion exchange chromatography was used to separat the solution after the preliminary separation and charactenization by ultrafiltration and gel permeation chromatography. The eluent p H, ionic strength, velocity of the three factors were studied. The optimal conditions for analysis were as follows : elution of p H = 6. 0, the flow rate was0.8m L/min, the ionic strength was 1.0mol/L. The results showed that the fraction was then purified by ion exchange chromatography into 3 peaks, in which peak 1 had the strongest ACE inhibitory activity with an IC50 of 0.1012mg/m L. And the peak 1 was further desalinationted by gel permeation chromatography to obtain 4peaks, and the peak 2 had the highest ACE-inhibitory activity with an IC50 of 0.0836mg/m L, the desalination rate 86.60%±0.5%.