Abstract： Objective:To investigate the predictive value of albumin/fibrinogen ratio (AFR) for 28-d mortality in patients with sepsis.Methods:A total of 186 patients with sepsis admitted to the Intensive Care Unit of the First Affiliated Hospital of Xinjiang Medical University from January 2019 to December 2021 were studied retrospectively. They were divided into the survival group ( n=124) and death group ( n=62) according to the 28-d survival conditions. Clinical data of each group within 24 h after admission were recorded, including age, sex, underlying diseases, white blood cell count, albumin, fibrinogen (FIB), PCT, CRP and other laboratory examination indexes. APACHEⅡ scores and SOFA scores were recorded at the time of admission. Cox regression was used to analyze the influence of each index on the prognosis of patients. Receiver operating characteristic (ROC) curve was used to analyze the predictive value of AFR for 28-d mortality in patients with sepsis. Kaplan-Meier method was used to draw survival curves under different AFR levels for survival analysis. Pearson correlation was used to analyze the relationship between AFR and APACHEⅡ score. Rseults:Age, number of patients with septic shock, mechanical ventilation, APACHEⅡ score, SOFA score, blood lactic acid and fibrinogen increased significantly in the death group ( P<0.05), while albumin and AFR were significantly decreased ( P<0.001). ROC curve analysis showed that the area under the curve of AFR in predicting 28-d mortality risk of patients with sepsis was 0.900. When the cut-off value of AFR was 7.64, the sensitivity was 80.0% and the specificity was 85.5%. Kaplan-Meier survival analysis showed that patients with AFR >7.64 had better prognosis. Cox regression analysis showed that AFR, APACHEⅡ score and the presence of septic shock were independent risk factors affecting the prognosis of patients with sepsis. AFR was strongly correlated with APACHEⅡ score ( r=-0.462, P<0.001). Conclusions:As a simple, effective and safe biomarker, AFR has a certain predictive value for 28-d mortality risk in patients with sepsis.