Polyphenolic complexes (PPCs) extracted from core wood and cell culture of Maackia amurensis decrease the acute toxicity of tetrachloromethane, suppress the necrosis of hepatocytes and the cellular infiltration in liver parenchyma, prevent the development of fatty and protein dystrophy in the liver, normalize the activity of aminotransferases and gamma-glutamyltransferase in the blood, restore the protein and lipid content, and stimulate the conjugation of bilirubin. The therapeutic effect was more pronounced for the PPC obtained from the cell culture. The hepatoprotector effect of the PPCs is due to the presence of isoflavonoids, including daidzein, retusin, genistein, afromosin, formononetin, orobol, tektorigenin, maakiain, and medicarpin. Ther PPC from the cell culture of Maackia amurensis does not affect the blood cholesterol level, which is probably explained by the absence of mono- and dimeric stilbenes in this cell culture.