2. Exclusion criteria (1) Episodes of overt hepatic encephalopathy (HE), esophageal gastric variceal bleeding (EGVB) or spontaneous bacterial peritonitis (SBP) within one month (2) Hepatitis B Virus (HBV) DNA ≥ 500 copy/ml (3) Standard antiviral treament duration less than six months for patients receiving antiviral treatment for hepatitis B or hepatitis C (4) Planned to receive or change the antiviral treament projects at the screening (5) Unwilling to stop alcohol abuse after inclusion (≥20 g/ d for women or ≥40 g/d for men) (6) Serum total bilirubin ≥ 170 μmol/L (7) Serum sodium level < 125 mmol/L (8) White blood cell count < 1×109/L (9) Serum creatinine ≥ 1.2 fold of upper limits of normal (10) Clinically diagnosed or suspected as liver malignancy (11) Previous use of antibiotics within two weeks before inclusion (12) HIV seropositivity (13) Poorly controlled hypertension, diabetes mellitus or other severe heart and lung diseases (14) Known hypersensitivity to rifaximin (15) Pregnancy and lactation woman (16) Participated in other studies within three months before screening (17) Not suitble for participating the study judged by investigators