Young children with liver cirrhosis have a significantly high risk of mortality. However, there are few studies regarding early childhood-onset cirrhosis. This study aims to explore the causes, clinical findings and prognosis of biopsy-proven cirrhosis in infants, toddlers and preschoolers. We enroled young children with biopsy-proven cirrhosis from January 2010. Till January 2020, the study has been going on for 10years. A total of 139 cirrhotic children were enrolled, including 87 boys and 52 girls. The median age at initially histological diagnosis of cirrhosis was 2years old (range: 1month-6years). Sixty-two patients reported yellowish discoloration of sclera and/or skin as an initial symptom. Ninety-three patients had definite aetiologies while 46 had indeterminate causes. Among the confirmed cases, 31 had hepatitis B virus (HBV) infection, accounting for 33.3%. Subsequently, glycogen storage disease was diagnosed in 16 cases and Wilson disease in 14 cases. In these patients with HBV infection, nine finally achieved hepatitis B surface antigen (HBsAg) loss (29.0%) after effective antiviral therapy during the follow-up. Logistic regression revealed that baseline alanine aminotransferase (odds ratio 1.008, p=0.028) was the independent predictor of HBsAg loss. Furthermore, one patient who underwent second biopsies showed histological reverse. HBV infection is an important cause of paediatric cirrhosis in our study. The pathogenesis of HBV-related cirrhosis in early childhood deserves further studies.