Binding ability of blood serum albumin was decreased in patients with thermic burns as well as in rats with burns. Loss of this albumin property did not depend on decrease of its content in blood serum; in the patients with burns the decrease in albumin binding ability correlated with development of encephalopathic symptoms. After treatment of blood serum from experimental animals with hemosorbent the blood serum binding ability was distinctly restored in vitro. At the same time, hemosorption did not affect the binding ability of blood plasma in patients with burns. Importance of alterations in binding ability of blood serum albumin for development of acute burns toxemia is discussed.