The aim of this study was to determine an appropriate range of negative pressure to ensure the treatment effect of cupping. Twenty healthy participants were enrolled to receive classic dry cupping treatments at three different pressure intensities (−100, −300, or −500 mmHg) for 10 min each. Heart rate variability (HRV) was measured before, during, and 10 min after cupping to assess changes in autonomic activity. Repeated measure ANOVA was used to analyze differences. Cupping at a pressure of −100 mmHg did not significantly change the HRV, but cupping at both −300 and −500 mmHg caused a significant improvement in HRV. The HRV responses did not differ significantly between cupping at −300 and at −500 mmHg, however. The significant increase in HRV occurred only during the recovery period after the cups were removed.