Delirium is an acute syndrome of disorientaion caused by dysfunction of brain and has many various symptoms. The characteristic symptoms of delirium are conscious disturbance with disorientation, dysarthria and emotional disturbance. We experienced 84-year-old man who had Wi syndrome(?證) as well as delirium during the treatment of pneumonia, and whose condition was improved through Oriental medical treatment. The patient was diagnosed as Yangmyeong Disease(陽明病) that was caused by heat in the stomach and stool in the colon, and was treated with Daeseungki-tang (Dachengqi-tang, 大承氣湯). We were able to improve the delirium caused by high fever infection through Oriental medical treatment.