Abstract: OBJECTIVE To investigate serum expression of serum soluble myeloid cell trigger receptor-1（sTREM-1）, interleukin-1β（IL-1β） and soluble leukocyte differentiation antigen 14（sCD14） in patients with infection after thoracic surgery and to analyze the effect on the prediction of infection and prognosis. METHODS From Mar 2017 to Dec 2019, 113 patients with postoperative infection after thoracic surgery in Nantong University Hospital of Jiangsu Province were recruited in the study group; 113 patients without infection after thoracic surgery during the same period were enrolled in the control group. The serum levels of sTREM-1, IL-1β and sCD14 were compared between the two groups and in patients with different prognosis in the study group. Multivariate Logistic regression analysis was used to analyze the risk factors for infection after thoracic surgery. The receiver operating characteristic（ROC） curves and the area under ROC（AUC） were used to evaluate the value of each index in predicting postoperative infection after thracic surgery. Cox regression was used to analyze the related factors affecting the prognosis of infection. RESULTS The serum levels of sTREM-1, IL-1β and sCD14 in the study group were significantly higher than those in the control group（P＜0.05）; the AUCs of sTREM-1, IL-1β, and sCD14 in the prediction of post-thoracic surgery infections were 0.722, 0.806 and 0.814, respectively; and AUC of the combination of the three indicators was 0.898. The serum levels of sTREM-1, IL-1β and sCD14 in the dead of the study group were significantly higher than those in the living（P＜0.05）. APACHEⅡ score, SOFA score, sTREM-1, IL Serum levels of-1β and sCD14 level were risk factors for the poor prognosis of infection after thoracic surgery（P＜0.05）. CONCLUSION Serum sTREM-1, IL-1β, and sCD14 are highly expressed in patients with postoperative infec-tion after thoracic surgery, which may have good effect on the prediction of infection and evaluation of prognosis.