Objective To understand nurses' cognition and behaviour on the management of ventilator circuit in intensive care units (ICUs) of hospitals at all levels in Jiangsu Province, and provide reference for standardizing health care workers' management on ventilator circuit. Methods Self-designed survey questionnaires and conve-nient sampling were adopted to investigate ICU nurses. Results 575 questionnaires were finally collected, with an effective response rate of 93.57%. 538 ICU nurses from 63 hospitals in 13 cities participated in the survey. Four types of ventilator circuits used in hospitals were investigated, including disposable double heating ventilator circuit (49 hospitals, 77.78%), disposable anaesthesia ventilator circuit (46 hospitals, 73.02%), disposable single hea-ting ventilator circuit (34 hospitals, 53.97%), and repeated disinfectant reusable silica gel circuit (22 hospitals, 34.92%). A total of 12 brands of ventilator circuits used in hospitals were investigated, with Fisher & Paykel being the most popular (28 hospitals, 44.44%), followed by Comen (18 hospitals, 28.57%). Besides replacing ven-tilator circuit when there was visible contamination or circuit dysfunction, 44.61% (240/538) ICU nurses would judge whether ventilator circuits need to be replaced based on their clinical experience. ICU nurses believed that intermittent turning off machine (79.93%), multidrug-resistant organism infection (84.20%), and inhalation therapy (83.83%) could/might impact the duration of ventilator circuit use. 21.00% (n=113) ICU nurses were aware of the incidence of ventilator-associated pneumonia (VAP) in their departments in 2021. Conclusion Multiple types and brands of ventilator circuits are used clinically. There is no unified replacement frequency for ventilator circuit. Currently, common replacement frequency is every 7 days. It is recommended to replace ventilator circuit according to the nursing care process and the standards of hospital or department.