Objective:To present evidence for the pathogenetic role of allergic factor,histamine,in type I allergy for induction of liver damage.Methods:Three groups of rabbits were fed normally and injected (iv) daily with 0, 0.04 or 0.08 ?g/kg phosphohistamine, respectively, for days. The serum level of ALT and AST in each group rabbits was assayed dynamically during the treatment. After treatment for days, the tested rabbits were sacrificed for pathological examination of the liver tissues.Results:The serum level of both ALT and AST in rabbits treated with phosphohistamine increased significantly during the tested periods, compared to that of the control group. However, both ALT and AST levels showed no significant difference between 0.04 ?g/kg and 0.08 ?g/kg groups. Liver microscopic examination, pathological damage could be observed in the tested groups in a time-and dose-dependent manner under microscopic examination. No evident pathological change appeared in the control group.Conclusion:Liver damage could be induced by histamine dosage-and time-dependently. This pathological action of histamine, a type I allergic factor, presents further evidence for a direct role of type I allergy in the pathogenesis hepatic injury.