BACKGROUND The aim of this study was to analyze amplitude-integrated electroencephalography (aEEG) in early diagnosis and prognosis of hypoxic encephalopathy (HE) in premature infants. MATERIAL AND METHODS Thirty-six premature infants with HE who were treated in Linyi Central Hospital were enrolled into the study group, while 40 premature infants without HE were assigned into the control group. aEEG was conducted within 6 h after delivery to compare aEEG continuity, mature sleep-wake cycle, and maximum and minimum voltage in the 2 groups. Correlations between aEEG abnormalities and clinical grading, neurological prognosis, Apgar score, and blood gas were also analyzed among the premature infants with HE. RESULTS Compared with the control group, there were reductions in the continuous rate of aEEG, mature sleep-wake cycle, and the minimum voltage, and an increase in the maximum voltage in the study group (all P<0.05). The study group had a higher abnormal rate of aEEG and a lower normal rate of aEEG than in the control group (both P<0.05). Spearman's rank correlation coefficients for abnormal aEEG and clinical grade and poor neurological prognosis were 0.758 and 0.799, respectively. The sensitivity of abnormal aEEG in predicting severity of clinical grading was 100% with a specificity of 82.5%. The sensitivity of abnormal aEEG in predicting neurological prognosis was 100% with a specificity of 90.3%. The Apgar scores and blood glass pH of the infants with various abnormal rates of aEEG were significantly different at 1 min, 5 min, and 10 min after delivery (all P<0.05). CONCLUSIONS HE in premature infants has specific aEEG characteristics, which can be used to predict the severity and prognosis of HE.