Objective：To explore the relationship between death cause and vaccine injection and to provide references for coincidental event prevention and vaccination safety. Methods：Data of 31 infants died within 8 d after vaccination were analyzed retrospectively. Results：Male：female ratio was 2.9∶1. Minimum age was 32 gestational weeks and maximum age was 2 years. All 31 cases were coinci－dental event；21 infants died due to vaccination exacerbating the potential infectious diseases without typical symptom and 10 cases had no relationship with vaccination. Conclusion：Intensifying physical examination and inquiry before vaccination is an important method for decreasing coincidental event. It is the key measure to deal with the disputes by autopsy.