To study the effects of Chinese medicinal preparation on the removal of bacterial colonization in oropharynx and the incidence and pathogen of ventilator-associated pneumonia(VAP) in critically ill patients.Methods:A total of 140 patients who received mechanical ventilation in the Intensive Care Unit(ICU) of the Affiliated Hospital of Qingdao University from March 2019 to September 2020 were selected and randomized into a control group(n=70) and an observation group(n=70).Both groups received routine treatment.In addition，the control group was treated with compound chlorhexidine gargle and the observation group B with Chinese medicinal preparation.Different gargles were used to clean the oropharynx and subglottic retention every 6 h and then removed by a suction tube.The bacteriological characteristics，duration of mechanical ventilation，length of ICU stay，VAP incidence，28-day mortality rate，and species and distribution pathogenic bacteria in the subglottic retention were compared between the two groups.Results:The observation group had fewer colonies in the subglottic retention after mechanical ventilation than the control group(P<0.05)，demonstrating the potential of inhibiting the VAP caused by Gram-negative bacteria(P<0.05).The total duration of mechanical ventilation in the observation group was shorter than that in the control group(P<0.05).The incidence of VAP，length of ICU stay，and 28-day mortality rate showed no significant differences between the two groups（P>0.05）.Conclusion:Compared with compound chlorhexidine gargle，the Chinese medicinal preparation can effectively remove bacterial colonization in the oropharynx and subpharynx and has the potential to reduce the incidence of VAP，being safe，effective，and highly comfortable.Therefore，it has a high clinical application and promotion value.