OBJECTIVE To investigate the bacterial contamination status of ventilator systems and corresponding measurements.METHODS Bacterial culture samples of auxiliary equipments of 36 ventilators,including inlet and outlet tube,mask,humidifier,water collector,nebulizer,and air filter,were respectively collected.The culture results were reported to the infectious disease control office of the hospital.After improved the sterilization management,then repetition of bacterial culture was performed and the results were compared with the former.RESULTS The first cultural results demonstrated severe bacterial contamination and the positive rate of inlet tube,humidifer,water collector,nebulizer,and air filter was even higher than 50%.After countermeasures were conducted,the positive rate of second bacterial culture of all ventilator systems was significantly dropped to less than 5.5%.CONCLUSIONS Bacterial contamination of ventilator systems commonly exists which can be significantly diminished by improved conception of asepsis and standardized sterilization.