The texts of "Hwangjenaegyeong(黃帝內經)" explains Hakjil(?疾) in detail, especially in the "Jahak(刺?)" chapter, where bloodletting treatment is applied in many cases. The following paper categorized and organized Hakjil(?疾) cases treated by bloodletting methods, then analyzed applicable subjects and appropriate time for the procedure based on the texts. Afterwards, the mechanism for the cessation of Hakjil(?疾) seizures was examined. The findings of this research are as follows. 1. In the contents of "Hwangjenaegyeong(黃帝內經)", the appropriate time for acupuncture and bloodletting procedure is when Hakjil(?疾) seizures start to present themselves. 2. When a seizure takes place as a symptom of the body getting rid of the Hak(?) pathogen, Yanggi(陽氣) rushes to the locus of the pathogen, causing congestion of Gi(氣) and Blood(血) resulting in static blood[瘀血]. Therefore, bloodletting at the time of seizure initiation helps the flow of Gi(氣) and Blood(血), preventing the rush of Yanggi(陽氣). This is a restoration of the balancing function of Eum(陰) and Yang(陽), which indicates that bloodletting not only promotes smooth flow of Gi(氣) and Blood(血), but extends its effects to mental functions that balances Eum(陰) and Yang(陽). 3. Although Hakjil(?疾) seizures are presented in terms of Gi(氣) and Blood(血) in symptoms such as chill and fever[寒熱], static blood[瘀血], pain, etc., a fundamental disturbance in mental functions that control cold and heat seems to be present.