Abstract: Objective To construct a model of concanavalin A(Con A)-induced autoimmune liver injury and to observe the effects of quercetin on Con A-induced autoimmune liver injury in mice.Methods Forty-eight mice were assigned randomly into six groups, including normal control group, model group, dexamethasone group and low-, moderate-, and high-dose quercetin groups(100, 200 and 400 mg/kg).Quercetin(or solvent for control group)were gavaged for 7 days continuously, then 15mg/kg Con A(or solvent)was given to the mice intravenously and dexamethasone was injected intraperitoneally 30 minutes before the injection of Con A.Two and six hours after the treatments, serum of the mice was collected to detect tumor necrosis factor alpha(TNF-α), interleukin 1 beta, (IL-1β), interleukin 6(IL-6), alamine aminotransferase( ALT), aspartate aminotransferase(AST), and lactic dehydrogenase(LDH), respectively.Liver and spleen were weighed to compute organ coefficient.Results Compared with the control group, ALT, AST, and LDH in the model group(1 214.20±168.03, 1 079.40±168.05, and 2 748.00±508.98 U/L)were significantly increased(P<0.01).TNF-α, IL-1β, and IL-6 in the model group(580.67±157.01, 231.67±119.4, and 14 077.5±9 699.09 pg/ml)were significantly increased(P<0.01).Compared with the model group, ALT, AST, and LDH in high-dose quercetin group(204.20±31.62, 372.60±29.85, and 1 923.40±418.63U/L)were significantly reduced(P<0.05).TNF-α, IL-1β, and IL-6(339.67±76.73, 108.33±21.47, and 7 068.33±3 414.4 pg/ml)were reduced significantly(P<0.05).Liver, spleen organ coefficients were not significantly changed.Conclusion Quercetin may have protective effect on autoimmune liver injury induced by Con A in mice.