Abstract: Objective　To investigate the relationship of insulin resistance (IR) with heart rate variability (HRV), heart rate deceleration (DC) and heart rate acceleration (AC) in school-age obese children. Method　A total of 83 obese children aged 6~10 years were selected and their to insulin resistance index (IRI) were calculated based on fasting blood glucose and fasting insulin value. The subjects were divided into IR group (45 cases) and non IR group (38 cases) according to the IRI value. In the same day of detection of fasting blood glucose and fasting insulin, 24 h dynamic electrocardiogram was performed. The indicators of DC, AC and HRV in group IR and group non IR were calculated and compared, and their correlations were analyzed. Results　In IR group, the DC, standard deviation of normal RR intervals (SDNN), standard deviation of the 5-minute average RR intervals (SD ANN) and high frequency (HF) power of children were lower than those in non IR group, while AC was higher than that in non IR group, and there were significant differences (P<0.05). The IRI in obese children was significantly negatively correlated with DC, SDNN, SDANN, root mean square successive differences (RMSSD), low frequency (LF) power and HF (r=−0.475~−0.249， P<0.05), while it was significantly positively correlated with AC (r=0.488， P<0.01) in obese children. Conclusion　Compared with non-IR obese children, IR has serious damage to autonomic nerve function and mainly manifestations are the decreased vagus nerve tension. The higher IRI has the lower vagus nerve tension.