Abstract: AIM To investigate diagnostic values of deceleration capacity (DC) and heart rate variability (HRV) in vasovagal syncope (VVS) middle-aged and elderly patients. METHODS Fifty-seven patients with unexplained syncope underwent head-up tilt test (HUTT) and Holter monitoring. According to HUTT results, they were divided into two groups:HUTT positive (25 cases) and HUTT negative (32 cases). The DC and HRV of the two groups were analyzed. The receiver operating characteristic (ROC) curve was used to explore the diagnostic values of DC and HRV. RESULTS The DC and HRV in the HUTT positive group were higher than those in the HUTT negative group. There were significant differences in DC, SDNNi, rMSSD and LF. ROC analysis demonstrated that DC and LF could be considered as indicators for diagnosing VVS. The best cut-off value of DC and LF were 6.6 ms and 340Hz, respectively. CONCLUSION The dysfunction of the autonomic nervous system may be seen in the VVS middle-aged and elderly populations during an asymptomatic period. DC and LF are suitable for clinical screening in VVS in the middle-aged and elderly populations.