ObjectiveTo investigate the differences in clinicopathological features and prognosis between patients with drug-induced vanishing bile duct syndrome （VBDS） and those with VBDS induced by autoimmune liver disease， and to summarize the key points for clinical differentiation. MethodsA total of 67 patients who were diagnosed with VBDS by liver biopsy in The First Affiliated Hospital of Soochow University and Wuxi Fifth People’s Hospital from January 2018 to June 2024 were enrolled as subjects， among whom 18 had drug-induced VBDS （D-VBDS group） and 49 had VBDS induced by autoimmune liver disease （A-VBDS group）. Related data were collected， including general information， clinical symptoms and signs， laboratory markers， liver pathomorphological features， and prognosis. The independent-samples t test was used for comparison of normally distributed continuous data between two groups， and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups； the chi-square test or the Fisher’s exact test was used for comparison of categorical data between two groups. ResultsAmong the 67 VBDS patients， female patients accounted for a higher proportion （80.60%）， and the patients aged 40 — 59 years accounted for 55.22%； there were 18 patients （26.87%） with D-VBDS and 49 patients （73.13%） with A-VBDS. Yellow urine （83.58%） was the most common clinical symptom in VBDS patients， followed by fatigue （64.18%）， poor appetite （64.18%）， jaundice of the sclera （62.69%）， abdominal distension （23.88%）， pruritus （23.88%）， nausea and vomiting （20.90%）， and fever （13.43%）. Compared with the D-VBDS group， the A-VBDS group had a significantly higher degree of plasma cell infiltration and a significantly lower degree of canalicular bile plugs （χ²=14.186， 6.568， both P<0.05）. Compared with the A-VBDS group， the D-VBDS group had significantly higher peak levels of alanine aminotransferase， total bilirubin， direct bilirubin， and indirect bilirubin （Z=-2.546， -2.957， -2.628， -2.772， all P<0.05）. Compared with the D-VBDS group， the patients in the A-VBDS group were more likely to develop liver cirrhosis （χ²=4.682， P=0.030）. ConclusionThe levels of alanine aminotransferase and bilirubin and liver pathomorphological features are objective indicators for differentiating D-VBDS from A-VBDS， and they are of great importance for clarifying diagnosis and determining the degree of liver injury. Patients with A-VBDS are more likely to develop liver cirrhosis.