The Acute Respiratory Distress Syndrome (ARDS) is one of common clinical critically diseases. In the United States, the incidence of ARDS reaches 31%, which is one of the main causes of death in patients. There is no unified treatment process for ARDS currently and the treatment measures are not yet standardized, so the standardization of ARDS treatment processes is needed to reduce mortality in patients. Following the evidence-based medicine principles and six-step treatment standards of ARDS, this study uses the method of multi-center randomized controlled clinical trials to evaluate the standardized treatment process of ARDS, which provides the basis for the standardized treatment of ARDS.

From September 1st 2012 to September 30th 2014, all ARDS patients admitted to the ICUs will be enrolled. The demographic characteristics, diagnosis, formerly medical history, Ventilator indications, Ventilator data, other respiratory treatments, weaning outcome and 28 day mortality will be recorded.

Inclusion Criteria:

1. aged ≥ 18 years
2. admitted to the ICU
3. according to the diagnostic criteria of ARDS Berlin definition，admit patients with severe ARDS

Exclusion Criteria:

1. age <18 years old
2. be expected to die within 24 hours
3. end-stage malignancies
4. be participating in other studies, which may affect the results of this study
5. DNI (do not intubation) and DNR (do not recovery) patients
6. family members do not agree to sign an informed consent