Abstract:Objective To study characteristics of heart rate variability (HRV) in the normal newborns. Methods Compas XM Holter system was used to analyze the time domain of HRV in 35 normal newborns. Results There was no difference in the parameters of HRV and heart rate indexes of newborns in the early period (1~7 d) and later period (8~28 d). There was moderate negative correlation between the standard deviation of all normal RR (SDNN) and the heart rate varibility index (HRVI) and average heart rate and minimum heart rate ( r :-0.44,-0.43,-0.51,-0.56, respectively P<0.05).Conclusions HRV parameters are stable indexes that reflect the function of the cardiac autonomic nervous system. The results may be referred to in the study of newborns' HRV.