Objective To analyze the the characteristics,risk factors and treatment of trastuzumab-induced hepatotoxicity in patients with breast cancer.Methods To analyze by a case report of trastuzumab-induced hepatotoxicity in a patient with breast cancer in practice combined with 4 related case reports in literatures.Results and conclution Trastuzumab-induced liver toxicity may have the following characteristics:early occurrence;previous use of medication with the side effect of liver damage may be one of the causes of hepatotoxicity;the grade of hepatotoxicity often reaches grade 3 and grade 4;long duration of liver function recovery;hepatotoxicity induced by trastuzumab may be dose-related.Focusing on past medical history and medication history and regular monitoring of liver function may be one of the effective measures to determine hepatotoxicity intensively and to avoid serious complications.