Macroporous alumina is synthesized via precipitation with sulfuric acid from a sodium aluminate solution. It is established that introducing a coagulating agent (sodium chloride) preventing macrogel formation makes it possible to obtain highly porous samples of alumina with specific surface areas of ~100 m2/g, a large pore volume of 1.6–1.7 cm3/g, and an average pore diameter of 50–75 nm. According to the adsorption isotherms and the pH dependence of hemoglobin adsorption that such samples have a high capacity for protein macromolecules. The maximum adsorption of hemoglobin is ~500 mg/g, and is observed at pH 6–7. Adsorption falls substantially when the pH is reduced to 4 or increased to 9, and it is close to zero at pH 11.