Objectives : The purpose of this study was to assess the effect of Hwangryunhaedok-tang pharmacopuncture at $CV_{17}$ for reducing mental stress using power spectrum analysis of the heart rate variability(HRV). Methods : 30 healthy volunteers(control group: 15, experimental group: 15) participated in this study. After instrumentation and 5-minutes rest period, mental stress by operation was provided for 5-minutes. HRV was recorded before and after the mental stress. And then the control group rested for 15-minutes. The experimental group was injected Hwangryunhaedok-tang pharmacopuncture at $CV_{17}$ and rested for 15-minutes. And then HRV was recorded. Results : In simple rest group, LF norm and HF norm showed a significant change after mental stress. In pharmacopuncture group, LF norm, HF norm and LF/HF showed a significant change after mental stress. But there were no significant difference between two groups(p>0.05). In pharmacopuncture group, LF norm, HF norm and LF/HF showed a significant change after pharmacopuncture injection. There were significant difference between two groups(p<0.01). Conclusions : The result suggests that Hwangryunhaedok-tang pharmacopuncture at $CV_{17}$(Jeonjung) can regulate and prevent the alteration of autonomic nerve system due to mental stress.