Abstract: Objective:To explore the clinical significance of heart rate variability in functional ventricular premature beat children of different ages.Methods:A total of 102 children with functional ventricular premature beat was randomly divided into three groups according to their ages:infant group，preschool group and school-age group.The HRV time domain value was measured in all the children with 24 dynamic electrocardiograms and the results were analyzed.Results:The percentage of differences exceeding 50 ms in the adjacent normal number of intervals,standard deviation of nn intervals，rMSSD,SDANN and SDSD were significantly higher in the preschool children group and school-age group than those in the infant group(P0.01).The PNN50,rMSSD and SDSD were significantly different between the preschool children group and the school-age group(P0.05).Conclusions:The autonomic nervous system of children will develop with the age;ventricular premature beat is closely related with the autonomic nervous function status and imbalances.