Hepatoprotective effect of 6-MFA, obtained from fungus Aspergillus ochraceus ATCC 28706, was evaluated by employing three different immunological liver injury mice models. The first liver injury model was induced by injecting anti-basic liver protein (BLP) antibody into mice previously immunised with rabbit IgG (RGG). The other models were simulated by injecting antiliver specific protein (LSP) antibody or by injecting bacterial lipopolysaccharide (LPS) into mice pretreated with Corynebacterium parvum (C. parvum). 6-MFA treatment inhibited the increased transaminases (GOT and GPT) activities and showed a tendency to inhibit the histopathological changes of the liver in all the models studied. Furthermore, 6-MFA treatment inhibited deoxycholic acid induced transaminase release from cultured rat hepatocytes in vitro, but failed to affect the formation of hemolytic plaque forming cells in immunised mice spleens and hemolytic activity of guinea pig complement in immunohemolytic reaction. Our findings, therefore, suggested that the moderate hepatoprotective effect of 6-MFA could be related to it's protective effect on hepatocyte plasma membrane rather than the direct inhibitory effects on the antibody formation and/or complement activity.