The effect of putrescine on oleic acid-induced RDS were studied in rat, it was found that preadministration of putrescine to rat with RDS significantly improved its hypoxemia, pulmonary edema and histologic injury; inhibited the leakage of protein from plasma; lowered increase of pulmonary lipid peroxidation products (malondialdehde, MDA). The result suggests that putrescine could have significant potential for clinical treatment of acute pulmonary injury.