Introduction & aim: Magnesium playes an important role in the structure and cell metabolism. In this research, an anti-oxidant effect of magnesium sulfate against oxidative stress effects of 4 CCL was investigated.Methods: In this experimewtal study 36 male adults rats were placed into4 groups, with nine rats in each group. Treatment was then carried out as follows. Group I received olive oil (INTRAPERITONEALLY) and distilled water (intragastrically), and served as the untreated control animal group. Group II was the hepatotoxicity group that was given a suspension of 4 CCL (i.p., 0.5 mL/kg b.wt, 50% 4 CCL in olive oil), twice a week. Groups III received 4 MgSO dissolved in distilled water daily via an intragastric tube (0.15M 2 g/kg b.wt.) Groups IV were the treatment group that received 4 MgSO dissolved in distilled water daily, via an intragastric tube 0.15 Mg2 g/kg b.wt.),with 4 CCL (i.p., 0.5 mL/kg b.wt., 50% 4 CCL in olive oil) twice a week. After a 28-day treatment period, the animals were deprived of food overnight, anesthetized by exposure to diethyl ether, and then sacrificed by decapitation. Blood ws collected from the jugular vein, and serum was separated and used for liver marker assays. Levels of ALT, AST ALP and GGT were estimated using commercial kits. The liver homogenates were used for the assay of SOD .All data were expressed as means S.E.M. Statistical analysis was carried out using one-way ANOVA followed by a Tukey post hoc test. The criterion for statistical significance was p<0.05.Results:In the 4 CCL -treated control group, serum ALT, AST, ALP and GGT were significantly increased as compared with the untreated control group. In contrast, the group that also received mgso4 Showed signifi cantlyless elevated levels of ALT, AST, ALP and GGT. Compared to normal levels. Liver SOD activity in 4 CCL -treated rats was decreased significantly when compared with the the control group. Treatment with 4 MgSO protected this enzyme activity.Conclusion:The results of this study showed that magnesium sulfate has improved oxidative effect of 4 CCL in the liver rats because of its antioxidant properties.