The hepatoprotective effects of the hot water (SRHW) and methanolic (SRM) extracts from the roots and stems of Salacia reticulata were examined using an oxidative stress-induced liver injury model. Both SRHW and SRM extracts (400 mg/kg, p.o.) significantly suppressed the increase in glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) activities in carbon tetrachloride (CCl₄)-treated mice. These extracts also inhibited CCl₄-induced thiobarbituric acid-reactive substance (TBA-RS) formation, which indicates increased lipid peroxidation in the liver. A good correlation (r=0.945, p<0.01) was observed between the amount of phenolic compounds in the extracts and their inhibitions of TBA-RS formation. The IC₅₀ values of the extracts on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging were less than 10 µg/ml and the antioxidative activities of six phenolic compounds from the roots of S. reticulata were examined. Mangiferin, (−)-4′-O-methylepigallocatechin, and (−)-epicatechin-(4β→8)-(−)-4′-O-methylepigallocatechin, which a principal phenolic compounds, showed potent scavenging activity on DPPH radicals and their concentrations required for 50% reduction of 40 µM DPPH radicals were 5.9, 10, and 3.2 µM, respectively. On the other hand, against the CCl₄-induced serum GOT and GPT elevations and TBA-RS formation in mice, mangiferin and (−)-4′-O-methylepigallocatechin showed potent activity at a dose of 100 mg/kg, but (−)-epicatechin-(4β→8)-(−)-4′-O-methylepigallocatechin did not. These results suggest that the antioxidative activity of the principal phenolic compounds is involved in the hepatoprotective activity of S. reticulata.