Abstract: In order to obtain high activity and purity of antihypertensive peptides,the method of RP-HPLC was used to separate the solution after the preliminary separation and charactenization by ultrafiltration,gel permeation chromatography and ion exchange chromatography. Studying the effect of separation and purification on the factors of elution conditions,the optimal conditions for analysis were as follows :0~5min 0%~80%A;5~8min80% ~100% A;8 ~15min 80% ~60% A;15 ~20min 60% ~20% A. The results showed that the fraction was then purified by frist RP-HPLC into 3 peaks,in which peak Z2 had the strongest ACE inhibitory activity with an IC50of0.0437mg/m L. The peak Z2 was desalinationted by the second RP-HPLC. The peak Z21 had the highest ACE inhibitory activity which with an IC50 of 0.0352mg/m L,the purity was 96.7%. Through the analysis of the amino acid of Z21 and identification of LC-MS,it contained six kinds of amino acids(Glu,Ala,Val,Leu,Phe,Pro),the molecular weight was 764.8.