Abstract: Cationic ion-exchange Separation process of L-phenylalanine with high salt concentration was investigated.One cationic exchange resin HD-1 with high adsorbance on L-phenylalanine was selected for the separation.The adsorbance of resin was near to 0.09g L-phenylalanine per milliliter resin.At the same time,the effects of concentration,velocity of flow and inorganic salt on L-phenylalanine adsorption were studied.The yield of separation process was close to 96.7%.