OBJECTIVE To investigate whether Renqing Changjue has a protective effect on acute respiratory dis?tress syndrome (ARDS) induced by endotoxin lipopolysaccharide (LPS) in rabbits. METHODS Thirty-six healthy male New Zealand white rabbits were randomly divided into six groups: normal control group, model group, dexamethasone group, Renqing Changjue high, middle and low dose group, with six rabbits in each group. LPS was used to replicate the ARDS model after five consecutive days of gavage. Arterial pressure, respiratory rate and anal temperature blood were recorded for arterial blood gas analysis at 0, 0.5, 1, 2 and 4 h, respectively. At the end of the four-hour experiment, rab?bits were killed by bloodletting, and the lung tissue was quickly removed to determine the cytokines, SOD, MDA and pathological examination of rabbit lung. RESULTS Renqing Changjue can significantly reduce the pathological changes of lung in ARDS model group. The expression of AQP1 and MPO in rabbit lung was significantly decreased by immuno?histochemistry (P<0.05) ,reduce the lung wet/dry weight ratio, increase the ratio of PaO2/FiO2, inhibit the release of inflammatory factors and scavenge free radicals and antioxidant effects. CONCLUSION Renqing Changjue can effec?tively protect rabbits with acute respiratory distress syndrome induced by LPS, and may protect the lung by inhibiting the release of cytokines and anti-oxidation.