Purpose : Studies on stroke were conducted by using the scaling system to estimate, compare severity and to predict prognosis. National Institute of Health Stroke Scale is widely used for this purpose due to its accuracy in predicting clinical symptoms. According to previous studies, neurologic symptoms in acute stage of ischemic stroke did not disappear, and approximately 27% to 43% of them were aggravated, We conducted this study to define clinical aggravation and to improve ischemic stroke in its acute stage by using NIHSS. Methods and Subjects : Due to their acute ischemic stroke, twenty five patients visited Wonkwang Oriental Medicine in Cheonju within forty eight hours from its beginning stage. Two oriental medicine doctors checked NIHSS every six hours during the first ninety six hours and later every twenty four hours for twelve days from the beginning of the disease. Results : The Aggravated group consisted of nineteen out of twenty five cases, which is seventy six % and NIHSS on admissions were $5.88{pm}0.63$ and it increased linearly over time by the equation of NIHSS on admissions was $8.50{pm}2.02$ and it decreased linearly over time by the equation of NIHSS=-0.01 one hour+7.91. Conclusion : During the study, we defined the clinical courses of acute ischemic stroke. There have been no reports on this so far. Therefore, we hope that this study will be beneficial to expand the scope of oriental medicine in dealing with aggravating ischemic stroke in the acute stage.