Abstract： Objective： To observe the effect of oral nursing with Shuanghua yin in prevention of ventilator- associated pneumonia(VAP). Methods：A total of 100 cases of patients supported by mechanical ventilation were randomly divided into the control group and the observation group，50 cases in each group. Both groups were given management of posture，air sac，ventilator pipe，sputum suctioning，and other nursing measures；the control group was additionally given oral nursing with sterilized cotton ball dampened with medical chlorhexidine； the observation group was additionally given oral nursing with Shuanghua yin. The treatment was carried out until the removal of mechanical ventilation. Duration of mechanical ventilation and hospital stays was recorded in the two groups. The incidence of VAP，the rate of fungal infection，and the incidence of oral diseases including halitosis，swollen gums，and oral ulcer were counted in the two groups. Results：The incidence of VAP was 16.00% in the observation group and 36.00% in the control group，the difference being significant(P＜ 0.05). The rate of fungal infection was 20.00% in the observation group and 46.00% in the control group，the difference being significant(P＜0.01). Duration of mechanical ventilation and hospital stays in the observation group were shorter than those in the control group， differences being significant(P＜0.01). The incidence of halitosis， swollen gums， and oral ulcer in the observation group were lower those that in the control group，differences being significant(P＜0.05，P＜0.01). Conclusion： Oral nursing with Shuanghua yin conduces to reducing the incidence of VAP and fungal infection， improving oral hygiene， shortening duration of mechanical ventilation and hospital stays，and effectively preventing VAP.