The purpose of this study is to examine the effects of Sasang constitutional herbal extracts, Cheongsimyeonjatang(CYT) on ECG(electrocardiogram). For this purpose, Ten hospitalized Taeumin patients were selected and changes of the ECG was investigated. The researcher also measured and observed ECG changes before and after CYT medication. The following is the summarized results of study. 1. The RV5+SV1 voltage was decreased in LVH patients. 2. The S-T voltage was decrease in the previous S-T elevated patients. 3. The heart rate was increased in the patients of lower heart rate than normal. 4. There was no remarkable change after medication on T-inversion and bundle branch block. From the above results, it is concluded that Cheongsimyeonjatang(CYT) have influenced on ECG.