Confirmed by ELISA, Clara cell secretory protein, Moesin, Matrix metalloproteinase 9 (MMP-9), Mucoprotein 5 AC and other proteins have been proved to be significantly different between the survival group and the non-survival group, which can be used as a potential biomarker to evaluate the prognosis of ARDS patients. Here, MMP9 is linked to acute respiratory distress syndrome.