Ion exchange and overoverequivalent sorption in the AV-17-2P-OH-Cl-tryptophan anionexchange system are studied. It is established that the ion exchange of tryptophan against the background of the exchange of mineral ions (OH--Cl-) is better accomplished from alkaline solutions on the Cl- form of the adsorbent and the overequivalent adsorption of an amino acid from a salt-containing solution on the OH- form of the anion exchange resin. The results from calculating and analyzing the thermodynamic constants of ion exchange and non-exchange absorption are given.