To investigate the protective effects of protopanaxadiol-type ginsenoside (PDG) and its metabolite ginsenoside M1 (G-M1) on carbon tetrachloride (CCl(4))-induced chronic liver injury in ICR mice, we carried out conversion of protopanaxadiol-type ginsenosides to ginsenoside M1 using snailase. The optimum time for the conversion was 24 h at a constant pH of 4.5 and an optimum temperature of 50 °C. The transformation products were identified by high-performance liquid chromatography and electrospray ion-mass spectrometry. Subsequently, most of PDG was decomposed and converted into G-M1 by 24 h post-reaction. During the study on hepatoprotective in a mice model of chronic liver injury, PDG or G-M1 supplement significantly ameliorated the CCl(4)-induced liver lesions, lowered the serum levels of select hepatic enzyme markers (alanine aminotransferase, ALT, and aspartate aminotransferase, AST) and malondialdehyde and increased the activity of superoxide dismutase in liver. Histopathology of the liver tissues showed that PDG and G-M1 attenuated the hepatocellular necrosis and led to reduction of inflammatory cell infiltration. Therefore, the results of this study show that PDG and G-M1 can be proposed to protect the liver against CCl(4)-induced oxidative injury in mice, and the hepatoprotective effect might be attributed to amelioration of oxidative stress.