Objective . Acute-on-chronic liver failure (ACLF) is a type of liver failure commonly found in China, and currently the mechanism of the disease remains unknown. This study aimed to investigate the epidemiology, clinical features and prognostic factors in ACLF. Methods . This study retrospectively included 170 patients with ACLF admitted to Beijing Friendship Hospital in Beijing, China from November 2017 to May 2019. Patients were divided into 2 groups: the improved group and the deteriorated group, according to the severity of their disease. Patients' demographic data; clinical manifestations; complications; laboratory indicators including platelets (PLT), alanine aminotransferase (ALT), aspartate amino transferase (AST), total bilirubin (TBIL), prothrombin time (PT), activated partial thromboplastin time (APTT), prothrombin activity (PTA), international normalized ratio (INR), and alkaline phosphatase (ALP) were collected. The relationship between these factors and the patients' prognosis were analyzed by logistic multivariate regression analysis. Results . The highest morbidity rate was in the age group 40 to 49 years (29.41%). The age group with the second highest morbidity was between 50 and 59 years (25.29%), followed by >60 (21.18%), 30 to 39 (20.59%), 20 to 29 (2.94%) and <20 years (0.59%). A total of 53 patients (31.18%) had a family history of hepatitis B virus infection. The patients' main clinical manifestations were ascites (77.65%) and weakness (68.23%). The most common complications were hypoalbuminemia (80%), infection (67.65%) and electrolyte imbalance (44.12%). In addition, the PTA (P = .009), hepatorenal syndrome (P = .005) and hepatic encephalopathy (level IV) (P = .005) were independently related to the prognosis of ACLF. There is a significant relationship between complications and prognosis (chi(2) = 8.502; P = .004). Conclusion . This study showed that prothrombin activity, hepatorenal syndrome and hepatic encephalopathy were independently related to the prognosis of ACLF. This outcome provided more options for reducing patient mortality in clinic.