Objective To investigate the family genetic characteristics of patients with vasovagal syncope (VVS). Methods A detailed family history of syncope was asked and recorded for documentation in 383 patients with unexplained syncope (UPS) who had a routine tilt test (HUTT). Results (1) A family history of syncope existed in 9.4% (36/383) of UPS patients, of whom 12.0% (23/191) were positive for HUTT and had a family history of syncope. (2) There were significantly more females than males with UPS, and those with a history of syncope in males had an 18.6% increased chance of syncope in their offspring (first-degree relatives), and those with a history of syncope in females had a proportion of syncope in their offspring (first-degree relatives) in females > males. (3) Causes of syncope were present in 21.7% (83/383) of patients with UPS and 39.1% (9/23) of patients with a family history of syncope and a positive HUTT. (4) The rate of mixed type was higher in patients with a family history of syncope and HUTT positive than in all HUTT positive patients (34.8% vs. 27.7%). (5) No difference (p>0.05) was seen between sex and age groups (<18 years vs. ≥18 years) in HUTT-positive patients with or without a family history of syncope. Conclusion There is a genetic predisposition to VVS, especially the offspring of first-degree relatives with a history of syncope have a significantly higher chance of syncope, and external factors can promote syncope.