Abstract: Objective:To explore the safety suction method for adult acute respiratory distress syndrome (ARDS) patients who received mechanical ventilation. Methods:Forty ARDS patients who received mechanical ventilation by implementation of artifical airway were randomly divided into experimental and control groups,20 cases in each group. The patients in experimental group were performed with closed endotracheal suction by the tee tubes without offline and the patients in control group were performed common open style suction. The variations of partial pressure of oxygen in artery(PaO₂),arterial oxygen saturation(SaO₂),heart vatel(HR), diastolic blood pressure (DBP) and systolic blood pressure (SBP) were monitored in each group. Results:In control group after endotracheal suction,the levels of SaO₂ and PaO₂ were decreased, the levels of SBP and HR were increased (P<0.01), and no significant change of DBP(P>0.05). In experimental group after endotracheal suction,there had no significant changes of the levels of SaO₂,PaO₂ and DBP,HR and SBP were decreased (P>0.05). Compared with control group,the changes of PaO₂ and SaO₂ had significant differences in experimental group(P<0.01). Conclusions:Closed endotracheal suction by tee tubes without offline can improve blood oxygen levels in ARDS patients who received mechanical ventilation and maintain hemodynamical stablity.