Objectives: This paper investigated the effects of 8 Constitution Acupuncture on Heart Rate Variability(HRV) and is intended to find out 8 Constitutional difference on Autonomous Function after 8 Constitution Acupuncture stimulation. Methods: The subjects were comprised of 42 volunteers(11 men and 31 women). The volunteers had acupunctured by 8 Constitution Acupuncture Therapy. HRV and Mean Heart Rate(MHR) were measured by TAS9v2.0(IEMBIO & Saerom, Korea) on two times: before and immediately after acupuncture stimulation. The SPSS 13.0 for windows was used for statistical analysis: Mann-Whitney U-test, Paired Samples T -test and Wilcoxon signed rank test were used to verify the results. Results: 1. There was no statistically significant difference on HRV and MHR between Sympathicotonia and Vagotonia before acupuncture. 2. In the whole subject, immediately after acupuncture stimulation, MHR showed a significant decrease(p<0.01) and Ln(TP), Ln(LF) and Ln(HF) showed a significant increase(p<0.05). But there was no significant difference in LHR. 3. Immediately after acupuncture stimulation, MHR showed a significant decrease and Ln(TP), Ln(HF), showed a significant increase in Pulmotonia(p<0.05), Ln(TP) showed a significant increase in Pancretonia(p<0.05),MHR showed a significant decrease and Ln(TP) showed a significant increase in Hepatonia(p<0.05), and MHR showed a significant decrease and Ln(TP), Ln(HF), showed a significant increase in cholecystonia(p<0.05). But there were no significant difference on HRV and MHR in Colonotonia and vesicotonia. Conclusion: The results suggest that 8 Constitution Acupuncture is associated with changed activity in sympathetic and parasympathetic nervous system. Further study is needed for investigating the effects of 8 Constitution Acupuncture on HRV and autonomic nervous system.