Abstract: 　Objectives　To observe the changes in heart rate deceleration capacity (DC), acceleration capacity (AC) and heat rate variability (HRV) and their correlation in healthy infants. Methods A total of 82 healthy infants who were divided into early infant group (<6 months) and late infant group (6-12 months) received 24 h dynamic electrocardiogram examination. The DC and AC value, time domain indices (SDNN, SDANN, RMSSD, PNN50) and frequency domain indices (LF, HF) of HRV were measured automatically by computer and compared between two infant groups. Moreover, the association of DC, AC value and HRV indices was analyzed. Results In late infant group, the DC value was (3.96±1.53) ms, higher than that in early infant group (3.20±1.44) ms, while the AC value was (-3.84±1.10) ms, lower than that in early infant group (-3.11±0.95) ms, and the differences were significant (P<0.05). The DC value derived from 24-hour Holter recordings was negatively related to heart rate (r=-0.56, P=0.000), while positively related to SDNN, SDANN, RMSSD, PNN50, LF and HF (r=0.25~0.75, P<0.05). The AC value derived from 24-hour Holter recordings was positively related to heart rate (r=0.78, P=0.000), while negatively related to SDNN, SDANN, RMSSD, PNN50, LF and HF (r=-0.88~-0.56, P<0.01). Conclusions The DC value and HRV indices are increased with age while AC value was decreased with age. The DC and AC value are closely associated with heart rate and HRV indices.