Abstract: It is well known that schizandra can markedly reduce the SGPT activity both in patients with hepaticdisease and in experimental animals, but the mechanism remains obscure.Our preliminary study in rabbits reveals that:Schizandra does not directly inactivate the SGPT activity to any significant degree nor does it reduce the permeability of the liver cell membrane for GPT release. In addition, schizandra does not markedly increase the SGPT clearance nor does it significantly protect the liver cell from CCl₄ intoxication. It was found that schizandra markedly reduced the GPT activity in the liver.The SGPT reducing effect of schizandra was found to be related to the time interval between the administration of the drug and the blood specimen collection. When the interval was 24 hours, the SGPT activity was not significantly affected; but if the interval was 2 hours, the SGPT was markedly reduced.It is concluded that schizandra is most likely a reversible enzyme inhibitor, its SGPT reducing effect is chiefly due to its reversible inhibition of the GPT activity in the liver cells. The clinicians must notice that the lowering of SGPT activity does not indicate that the lesions of the liver are restored or cured.