This study is clinical report for a acute stroke patient who was improved by treatment of a herbal medication. Stroke patients often shows spirit disorder in early stage. However, the cases which applied Onbyung theory are rare. This paper aims to show that Onbyung theory can be effective to acute stroke. We diagnosed the patient as invasion of the yong system by heat(熱入營分), which showed confusion, insomnia, delirium, anxiety, reddened tongue and dry mouth with cracked lip. After administration of Chungyung-tang(淸營湯) in Wen bing Tiao (溫病條辨), the patient showed those symptoms were highly improved. Thus, we concluded that Onbyung Theory can the patient be adapted to improve the symptom of acute stroke.