Objective To investigate the clinical features, etiology and prognosis of children patients with unexplained liver dysfunction. Methods The clinical data of 205 inpatients with unexplained liver dysfunction from January 2016 to December 2017 were analyzed retrospectively. The clinical characteristics, etiology and prognosis were analyzed. Results Of 205 patients with unexplained abnormal liver function, 166 patients with liver dysfunction (80.97%) were clearly diagnosed and involved in a variety of diseases. Among them, 104 cases were infected liver damage caused by non-hepatophilic virus, 38 cases were related to genetic metabolic diseases, 11 cases were drug-induced liver damage, 6 cases were Kawasaki disease, 4 cases were hematologic tumor diseases, 3 cases were malnutrition. The cause of abnormal liver function was not clear in 39 cases. Conclusion There are many and complicated causes of abnormal liver function, and part of the causes are unknown. Infantile liver dysfunction was mainly caused by non-hepatophilic virus, the first was cytomegalovirus, the second was Epstein-Barr virus; genetic metabolic disease, drug-induced liver damage, systemic disease are also an important cause of liver dysfunction.