Inclusion Criteria:  Men and women greater than or equal to 18 years of age; Baseline platelet count <50×10^9/L; End-stage liver disease, including acute-on-chronic liver failure, acute decompensation of liver cirrhosis, chronic liver failure; Women of childbearing potential must agree to use a highly effective method of contraception from the beginning of Baseline Visit until the end of treatment (includes implantable contraception, injectable contraception, hormonal combination contraception [including vaginal rings], intra-uterine devices or vasectomy). The barrier contraception with or without spermicide alone, double barrier contraception and oral contraceptives are inadequate; Subject is able to understand the study and willing to follow the protocol and sign informed consent voluntarily before Baseline Visit; Subject meet the criteria according to the opinion of the researchers.  Exclusion Criteria:  Subject has a history of arterial or venous thrombosis within the previous 6 months of baseline; Known portal vein blood flow velocity rate <10 cm/second or previous occurrence of a portal vein thrombosis within 6 months of Baseline; Known any history of primary blood (e.g, immune thrombocytopenia, myelodysplastic syndrome, aplastic anemia); Subject has a known medical history of genetic prothrombotic syndromes (e.g, Factor V Leiden prothrombin G20210A, antithrombin III (AT III) deficiency); Subject has a recent history (within the previous 6 months) of significant cardiovascular diseases (e.g., exacerbation of congestive heart failure, arrhythmias known to increase the risk of thromboembolic events [e.g. atrial fibrillation], coronary or peripheral artery stent placement or angioplasty, and coronary or peripheral artery bypass grafting); Female subjects who are lactating or pregnant at the Baseline Visit (as documented by a positive serum beta-human chorionic gonadotropin [β-hCG] test with a minimum sensitivity of 25 IU/L or equivalent units of β-hCG) or are planning to become pregnant during the study; The subject has a hypersensitivity to Avatrombopag or any of its excipients; Subjects with drug-induced thrombocytopenia; Subjects whose Life expectation ≤6 months; Subject with a current malignancy; Subjects with HIV infection; At screening, active infection was not effectively controlled by systemic antibiotic therapy; The Investigator believe that any accompanying medical history may affect the safety of the subjects to complete the study; The Investigator believe that there are any other factors that are not suitable for inclusion or affect participation or completion of the study; Subject is enrolled in another clinical study with any investigational drug or device within previous 30 days of the Baseline Visit, but are allowed to participate in observational studies.