Objective:To investigate the changes in the expression of toll like receptor 4 (TLR4), pentamerin-3 (PTX3) and Apelin in the blood of patients with sepsis and their relationship with the condition and prognosis.Methods:From March 2015 to March 2020, 82 patients with sepsis in the First People′s Hospital of Chenzou were retrospectively selected, including 22 patients in septic shock group, 34 patients in severe sepsis group and 26 patients in general sepsis group. 82 healthy people in the same period were selected as the control group. The expression of serum TLR4, PTX3, Apelin, Sequential Organ Dysfunction Score (SOFA), Acute Physiology and Chronic Health Score System Ⅱ (APACHE Ⅱ) were measured and compared. The relationship between the expression of serum TLR4, PTX3 and Apelin and the scores of SOFA and APACHE Ⅱ in patients with sepsis were analyzed. The general data and the expression of serum TLR4, PTX3 and Apelin in patients with sepsis with different prognosis (28 day survival and death) were counted. The influencing factors of prognosis in patients with sepsis were observed, and the predictive significance of serum TLR4, PTX3 and Apelin on the prognosis of patients with sepsis was analyzed.Results:Comparison of serum TLR4, PTX3 and Apelin level in the groups: septic shock group>severe sepsis group>general sepsis group>control group ( P<0.05); The serum level of TLR4, PTX3 and Apelin in patients with high SOFA and APACHE Ⅱ scores were higher than those in patients with low SOFA and APACHE Ⅱ scores ( P<0.05); Pearson correlation showed that serum level of TLR4, PTX3 and Apelin was positively correlated with the SOFA and APACHE Ⅱ scores of sepsis patients ( P<0.05); The levels of serum TLR4, PTX3, Apelin and the scores of SOFA and APACHE Ⅱ in the dead patients with sepsis were higher than those in survival patients ( P<0.05); Logistic regression analysis found that serum level of TLR4, PTX3, Apelin, SOFA score, and APACHE Ⅱ score were all important risk factors for 28 day death of sepsis patients ( P<0.05); The receiver operating characteristic (ROC) curve showed that the sensitivity and specificity of combined blood indexes (TLR4, PTX3 and Apelin) in predicting the prognosis of patients with sepsis were 85.71% and 85.25%. Conclusions:The expression of serum TLR4, PTX3 and Apelin in patients with sepsis can be significantly increased, which is related to the patient′s condition and prognosis and can provide a certain basis for clinical diagnosis and treatment.