Objectives : The aim of this study is to investigate the effect of Naegwan-acupuncture stimulation on the relationship of change in electrocardiopgraphy(ECG). Methods : For this purpose, 11 healthy volunteers were acupunctured at Naegwan acupoint using the reinforcing or reducing by inserting the needle in the same direction as the channel runs or in the opposite direction(迎隨補瀉). Then, we measured and observed the change of standard leads Ⅰ, Ⅱ and Ⅲ in ECG. Results : In lead Ⅰ, Naegwan acupuncture treated groups were increased the activity of PR interval and PR segment compared to the control group. In lead Ⅱ, Naegwan acupuncture treated groups were increased the activity of PR interval. In lead Ⅲ, Naegwan acupuncture treated groups were increased the activity of R wave duration, S wave amplitude, ST segment onset, ST segment midpoint, ST segment 80ms and ST segment endpoint. Conclusions : These results suggested that Naegwan acupuncture stimulation plays an important role to the activities of ECG