Abstract: 　Objective　To investigate the effects of caffeine on cerebral cortical activity in preterm infants. Methods　The preterm infants with 28-34 week gestational age and without asphyxia at birth were recruited as the subjects from January to September 2016. The infants who received conventional caffeine citrate were assigned to the caffeine group, while the infants with the same postmenstrual age did not receive any drugs that excite respiratory center were assigned to the control group. In the caffeine group, after the use of caffeine citrate stopped, the amplitude integration electroencephalogram (aEEG) recording were performed at 33, 34, 35 weeks of postmenstrual age. All the aEEG recordings were continuously monitored for at least 4 hours. The aEEG images were assessed by Burdjalov scoring system, and the interburst intervals were calculated. The effects of caffeine on preterm infants’ cerebral cortical activity in early life were analyzed. Results　In a total of 49 preterm infants recruited, 21 were in caffeine group and 28 in control group, and the ratio of male and female was 1.45:1. At the same postmenstrual age, the total score and individual scores of aEEG assessed by Burdjalov scoring system were not significantly different between caffeine group and control group. However, the length of interburst interval was significantly shorter in caffeine group than that in control group (P<0.05). All the recruited preterm infants had no seizure-like activity when the aEEG was monitored. Conclusion　The use of caffeine citrate has effects on EEG activity in early life of preterm infants, which may accelerate the brain maturation of preterm infants.