Abstract： Objective： To observe the clinical effect of the therapy of retention enema with Xuanbai Chengqi tang combined with linezolid injection on ventilator- associated pneumonia(VAP) in intensive care unit(ICU). Methods： A total of 102 patients with VAP were selected and divided into the control group and the observation group according to the random number table method，with 51 cases in each group. The control group was given intravenous infusion of linezolid injection， and the observation group was additionally given retention enema with Xuanbai Chengqi tang based on the treatment of the control group. The clinical effects in the two groups were observed， and the time of mechanical ventilation and ICU hospitalization was compared. Before and after treatment，the changes of scores of Clinical Pulmonary Infection Score(CPIS) and Acute physiology And Chronic Health Evaluation(APACHE)， arterial blood gas indexes， including PaCO2， PaO2， and PaO2/FiO2，indexes of respiratory mechanics，including airway resistance(Raw)，work of breathing(WOB)，peak inspiratory pressure(PIP)， and dynamic compliance(Cdyn)， and levels of serum related factors， including pentraxin- 3(PTX- 3)， proadrenomedullin( pro- ADM)， macrophage inflammatory protein- 2(MIP- 2) and C- reactive protein(CRP)， in the two groups were compared. Results：The total effective rate was 88.24% in the observation group and was 72.55% in the control group， the difference being significant(P＜0.05). After treatment，the scores of CPIS and APACHE in the two groups were decreased when compared with those before treatment，and the above two scores in the observation group were lower than those in the control group， differences being significant(P＜0.05). The time of mechanical ventilation and ICU hospitalization in the observation group was shorter than that in the control group， differences being significant(P＜0.05). After treatment， the PaCO2 content in the two groups was decreased when compared with that before treatment，and the PaO2 content and the lowest PaO2/FiO2 were increased；the PaCO2 content in the observation group was lower than that in the control group，and the PaO2 content and the lowest PaO2/FiO2 were higher，differences being significant(P＜0.05). After treatment，the values of Raw，WOB and PIP in the two groups were decreased when compared with those before treatment，and the Cdyn values were increased；the values of Raw，WOB and PIP in the observation group were lower than those in the control group，and the Cdyn value was higher，differences being significant(P＜0.05). After treatment，the serum levels of PTX-3，pro-ADM， MIP-2 and CRP in the two groups were decreased when compared with those before treatment，and the above four levels in the observation group were lower than those in the control group，differences being significant(P＜0.05). Conclusion：The therapy of retention enema with modified Xuanbai Chengqi tang combined with linezolid injection for VAP has a good curative effect，which can control the pulmonary infection and improve the respiratory function