This is a multicenter, randomized, double-blind, double-dummy, and positive control clinic trial which explores the efficacy and safety of ornithine aspartate granules in the treatment of non-alcoholic fatty liver disease against silymarin capsules. The hypothesis is that the ornithine aspartate granules have similar or better efficacy than the silymarin capsules.

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.