Inclusion Criteria:  1. Consistent with NAFLD diagnosis criteria, and during previous one month, the B-mode ultrasonography showed diffuse fatty liver and Fibroscan test showed that CAP value > 248 db/m; 2. During previous one month, serum ALT level was higher than 1.5 times the upper limit of normal. 3. BMI is not more than 30 kg/m2. 4. Voluntary to participate in the research and signed a written informed consent to comply with the trial protocol.  Exclusion Criteria:  1. Hereditary metabolic or autoimmune liver disease, hepatotropic and non-hepatotropic virus infection, drug/toxic/alcoholic/biliary liver injury, or any end-stage liver disease; fatty liver disease caused by one of the following reasons: total parenteral nutrition, inflammatory bowel disease, hypothyroidism, Cushing's syndrome, beta-lipoprotein deficiency and some insulin resistance (IR) related syndromes (lipid atrophic diabetes, Mauriac syndrome); 2. Hepatic or extrahepatic malignant tumors; 3. Severe heart failure or renal failure (serum creatinine > 3mg/100mL); 4. Allergic constitution, or allergic to amino acid drugs or to ornithine aspartate and its constituents or to silymarin; 5. ALT or γ-glutamyl transpeptidase (γ-GT) are greater than 5 times the upper limit of normal, or total bilirubin (TBIL) > 51 umol/L.; 6. Confirmed liver cirrhosis or Fibroscan test showed E value > 12.5 kilopascal (KPa); 7. Triglyceride > 5.6mmol/L; 8. Diabetes diagnosed for more than 5 years, combined with current insulin therapy or taking hypoglycemic drugs with poorly controlled condition (HbA1c > 9%). 9. Women who are pregnant, nursing or preparing for pregnancy; 10. Suspected or confirmed excessive drinking (equivalent alcohol amount: male, > 40g/d; female, > 20g/d), or history of drug abuse; 11. Combined use of drugs with liver protection and anti-inflammatory effects, as well as any Chinese patent medicine, Chinese herbal medicine, or health products that may have liver protection or liver damage effects; 12. Taking weight-loss drugs or receiving weight-loss treatment; 13. Situations of inappropriate participation judged by researchers.