Abstract: The purification and adsorption properties of fish scales polypeptides with angiotensin- I converting enzyme ( ACE) inhibitory activities treated by DA201- C macroporous adsorption resins were studied. Different eluted fractions were gotten by gradient elution of the adsorbate resins with different concentrations of ethanol ( 20%, 40%, 60%, 80%, v/v) .The relative molecular weight distribution range of different elution fractions had no significant difference, but the ACE inhibitory activity of the fish scales peptides increased. The IC50values of different fractions were 0.53, 0.40, 0.27 and 0.12mg /mL, respectively, when the ethanol concentration from 20% to80%.The results of adsorption thermodynamics experiment showed the adsorption process was endothermic, and increasing temperature was favorable to adsorption.The main force in the adsorption of fish scales polypeptides with ACE inhibitory activities on the surface of the DA201-C resins was hydrophobic.