Abstract: OBJECTIVE To analyze the occurrence of hepatic dysfunction induced by programmed death protein 1/programmed death ligand 1 inhibitor(PD-1/PD-L1) for the rational application in clinic. METHODS Twenty six patients with immune mediated hepatitis(IMH) after treatment with PD-1/PD-L1 inhibitor in Northern Jiangsu People's Hospital between July 2020 and March 2022 were enrolled for study. The age, sex, underlying disease, medication time of adverse drug reactions(ADRs), combined medication, clinical manifestations, liver injury types, treatment methods as well as prognosis were analyzed. RESULTS Among the 26 patients, aged 43-80 years, 22 males and 4 females were included. Grade ≥ 3 IMH was observed in 3 males and 3 females, and the incidence of grade ≥ 3 IMH was higher in females. The median time of adverse drug reactions occurrence was 27.5 d(2-248 d) after the medication. The 20 cases of grade 1-2 ADRs were all abnormal liver biochemical examination, while 6 cases of grade 3-4 ADRs were hepatocellular injury type(1/6), cholestasis type(2/6) and mixed type(3/6). After stopping the drug and/or symptomatic treatment, the time for recovery of liver function was 2-41 d, on the average of (18.45±9.89)d. After the recovery of adverse reactions, 19 patients continued immunotherapy, of which 8 patients had abnormal liver function again. The follow-up of 22 patients had a good prognosis of liver function. CONCLUSION Great attention should be paid to IMH induced by PD-1/PD-L1 inhibitor, especially in patients at early course or with prior IMH. Timely symptomatic treatment should be achieved especially for women who would be more likely to suffer severe IMH