Abstract： Objective To explore the therapeutic effect of non-invasive bi-level positive pressure ventilation in emergency treatment of acute lung injury induced by seawater drowning.Methods Sixteen cases of acute lung injury patients induced by seawater drowning were treated with bi-level positive pressure ventilation by using S/T mode,in addition to routine medical treatment.Then,a series of indexes,such as pH,PaO2,SaO2,HR,RR,SBP and DBP were detected,as well as changes in clinical symptoms before and after ventilation.Results After positive pressure ventilation treatment,clinical symptoms of all the patients improved significantly.Blood gas analysis indicated that pH (7.39 ± 0.02),PaO2 [(95.56 ± 4.10)mm Hg],SaO2 [(95.13 ± 2.06) ％] improved,when they were compared with those of before treatment [7.27 ± 0.03、(50.00 ± 4.71) mm Hg,(74.19 ± 6.11) ％],with statistical significance (P ＜ 0.05).Mechanical ventilation by tracheal intubation was avoided.Conclusions The application of non invasive bi-level positive pressure ventilation breathing machine for the treatment of acute lung injury induced by seawater drowning,skillful manipulation of the ventilation breathing machine and assurance of effective ventilation of patients by adjusting the breathing parameters of the breathing machine according to the illness status of patients,could effectively improve the symptoms and hypoxemia of patients.The non-invasive bi-level positive pressure ventilation breathing machine is a safe and effective device for emergency treatment of acute lung injury induced by seawater drowning.