Abstract: OBJECTIVE To explore the influencing factors for intraoperative transcranial Doppler ultrasound（TCD） couplant-induced nosocomial infection in the patients undergoing carotid endarterectomy（CEA） and observe the distribution of pathogens. METHODS A total of 166 patients who underwent CEA in the Chengde Central Hospital from Oct 2017 to Apr 2020 were enrolled in the study. The incidence rates of intraoperative TCD couplant-induced nosocomial infection and influencing factors were statistically analyzed, and the distribution of pathogens was observed. RESULTS Among the 166 patients who underwent CEA, the incidence of intraoperative TCD couplant-induced nosocomial infection was 22.29%. Logistic regression analysis showed that non-laminar flow operating room, non-disposable packaging of couplant, unsealed couplant and non-sterile couplant were the influencing factors for the intraoperative TCD couplant-induced nosocomial infection in the CEA patients（P＜0.05）. Partial correlation analysis indicated that non-disposable packaging of couplant, unsealed couplant and non-sterile couplant were still significantly associated with the intraoperative TCD couplant-induced nosocomial infection in the CEA patients after the factors such as age, non-laminar flow operating room, consecutive surgery and complication with diabetes mellitus were controlled（P＜0.05）. Totally 41 strains of pathogens were isolated from 37 patients with nosocomial infection, 19.51% of which were Staphylococcus hominis, 17.07% were Staphylococcus aureus, and 17.07% were Staphylococcus epidermidis. CONCLUSION TCD couplant has the risk to cause the nosocomial infection in the CEA patients, S.hominis is dominant among the pathogens. The risk of infection is closely associated with the factors such as non-laminar flow operating room, non-disposable packaging of couplant, unsealed couplant and non-sterile couplant, and it is necessary to pay attention to the disinfection of probes and hygiene quality of couplant.