Liver injury is elicited by a complex mechanisms involving free radical-induced oxidative stress, which can cause considerable injury to commercial laying hens. However, the effects of monoammonium-glycyrrhizinate in improving liver lipid metabolism and antioxidant capacity of laying hens is unclear. The current study examined the ameliorative effects of monoammonium-glycyrrhizinate (MAG) on liver lipid metabolism and antioxidant capacity in laying hens. One hundred eighty 320-day-old Hy-Line brown laying hens were allocated to five equal groups and administrated with the concentrations of 0 (control), 25, 50, 100, and 200 mg/L of MAG supplementation in the drinking water, respectively. The histological analysis results by Oil Red O and TUNEL staining showed that lipid deposition and hepatocytes apoptosis in the MAG treated groups were significantly lower than that in the control group. Blood biochemical indexes also revealed that MAG supplementation significantly decreased the activity of alanine aminotransferase (ALT) (p<0.05), the content of total protein (TP), albumin (ALB) and globulin (GLB) (p<0.05). Furthermore, supplementation of MAG increased the activity of total superoxide dismutase (T-SOD) (p<0.05), slightly increased the activities of total antioxidant capacity (T-AOC) (p>0.05) and catalase (CAT) (p>0.05). And the concentrations of malondialdehyde (MDA) were reduced in MAG groups, yet the differences were not significant (p>0.05). Notably, Liver weight, liver index, and triglyceride (TG) content were diminished significantly compared with the control group (p<0.05). These results demonstrated that supplementation of MAG to drinking-water of layers can enhance the antioxidant capacity, improve lipid metabolism and has a protective on liver injury, while no dose dependence was found in this study.