Abstract: Objective To explore the function of autonomic nerves system in children with congenital heart disease (CHD) combined with paroxysmal supraventricular tachycardia (PSVT). Methods Fifty children having PSVT and no CHD (PSVT group), 30 children with both PSVT and CHD (CHD group), and 50 cases of healthy children (control group) were selected. The difference of 24-hour heart rate variability (HRV) among three groups was analyzed retrospectively. Results There were statistical differences in the long-range time domain HRV indexes, including SDNN, SDANN, SDNN Index, pNN50, and RMSSD among three groups (F=80.32- 263.18, P all < 0.01). The SDNN, pNN50, and RMSSD in PSVT group were significantly decreased compared with control group (P all < 0.05), and the SDANN and SDNN Index in PSVT group were decreased but the difference was not statistically significant compared with control group (P all > 0.05). The SDNN, SDANN, SDNN Index, pNN50, and RMSSD were significantly decreased in CHD group compared with PSVT group (P all < 0.05). Conclusions Children with PSVT have the imbalanced autonomic nerves system which mainly manifests as decreased vagal function, and, if combined with CHD, have the increase of sympathetic nerve tension.