Inclusion Criteria:  RUCAM ≥6 and met one of the following biochemical conditions: (1) ALT≥5 ULN, (2) or ALP ≥2 ULN, (3) or ALT≥3 ULN and TBil≥2 ULN. RUCAM between 3-5, five experienced hepatologists in leading site evaluate and vote the diagnosis of DILI, the case would be enrolled if only ≥4 out of 5 hepatologists agree with the diagnosis. Onset to enrollment ≤3 months.  Exclusion Criteria:  Hepatotropic viral infection: hepatitis A, B, C, D and E. Non-hepatotropic viral infection: cytomegalovirus (CMV) and Epstein-Barr virus (EBV), etc. Hypoxic ischemic hepatitis and congestive liver disease. Alcohol consumption: male >40g/d, female >20g/d, and ≥5 years. Biliary obstruction, primary biliary cholangitis; primary sclerosing cholangitis. Autoimmune hepatitis: International Autoimmune Hepatitis Group (IAHG) simplified score ≥6 or complicated score ≥10, or differentiation from autoimmune hepatitis is impossible during enrollment. Parasitic infection. Sepsis. Previous liver transplantation or bone marrow transplantation. Pregnancy or lactation. Genetic and metabolic liver diseases.