Abstract: OBJECTIVE To explore the risk factors for postoperative biliary tract infection in malignant obstructive jaundice patients undergoing percutaneous transhepatic choledochus drainage（PTCD） and the diagnostic value of soluble CD14-subtype（sCD14-ST）. METHODS A total of 192 patients with malignant obstructive jaundice who underwent PTCD in the First Affiliated Hospital of Nanyang Medical College from Mar. 2017 to Mar. 2020 were recruited as the study objects and divided into the infection group with 80 cases and the non-infection group with 112 cases according to the status of postoperative biliary tract infection.The levels of C-reactive protein（CRP）, procalcitonin（PCT） and sCD14-ST of all the patients were detected before the surgery, the value of the three indexes in diagnosis of postoperative biliary tract infection was analyzed by using receiver operating characteristic（ROC） curve, and univariate analysis and multivariate logistic regression analysis were performed for the risk factors for the postoperative biliary tract infection in the PTCD patients. RESULTS The levels of sCD14-ST, CRP, and PCT of the infection group were significantly higher than those of the non-infection group（P＜0.05）; the levels of sCD14-ST, CRP and PCT were elevated with the aggravation of infection.ROC analysis showed that the Cut-off values of serum sCD14-ST, CRP and PCT were respectively 33.57 ng/ml, 11.38 mg/L and 0.57 ng/ml in diagnosis of postoperative biliary tract infection in the PTCD patients, and the area under curve of the sCD14-ST was the largest.The result of multivariate logistic regression analysis indicated that the more than 60 years of age, preoperative CONUT score no less than 2 points, history of biliary tract surgery and levels of three preoperative indexes were the risk factors for the biliary tract infection in the patients with malignant obstructive jaundice after PTCD（P＜0.05）. CONCLUSION The risk factors for the postoperative biliary tract infection in the malignant obstructive jaundice patients undergoing PTCD include the age, preoperative CONUT score no less than 2 points, history of biliary tract surgery and levels of preoperative CRP, PCT and sCD14-ST.It is necessary to take targeted prevention measures, and sCD14-ST has certain value in judgement of degree of infection and is worthy to be promoted in the hospital.