Oxymatrine (OMT) is an alkaloid isolated from Sophora alopecuroides L. The LD50 of OMT in mice by intramuscular injection was found to be 256.74±57.36 mg/kg.OMT (im) could diminish markedly ear inflammation in mice and rats induced by croton oil, and hind paw edema in rats induced by k-carrageenin. After intramuscular injection of OMT (51 and 85 mg/kg per day) and hydrocortisone (150 mg/kg per day) for 8 days in rats, the ear inflammation in rats induced by croton oil was decreased with anti-inflammatory ra...