Abstract： Objective To explore the relationship between urinary activin A and neonatal hypoxic-ischemic encephalopathy(HIE)by observing the change of urinary activin A in neonates with asphyxia,Provides the important basis for the HIE diagnosis and the condition judgment.Methods 50 cases of neonatal asphyxia term were the observation group ,48 cases of normal full-term newborns born in the same period were stochastically the normal control group.Within 7 days after birth,50 cases of neonatal asphyxia were divided into the group of 30 patients with mild HIE and the group of 20 patients with moderate and severe HIE,according to diagnostic criteria and clinical grading of neonatal hypoxic-ischemic encephalopathy.the levels of urinary activin A in two groups after birth different time(2,12,24,48,72 h) were determined by using ELISA method.Results The levels of urinary activin A in moderate and severe HIE group was significantly higher than the normal control group (P ＜ 0.01)and mild HIE group (P ＜ 0.01); The levels of urinary activin A in the normal control group and mild HIE group showed no significant differences (P ＞ 0.05).Urinary activin A levels ＞ 70 ng/L for the critical value to determine the occurrence of moderate and severe HIE,the sensitivity and specificity of 2 h urinary activin A levels were separately 82% and 99% ;the sensitivity and specificity of 12-72 h urinary activin A levels were separately 100%and 98%.Conclusion The correlation between the levels of urinary activin A and the severity of HIE was positive,the levels of urinary activin A had a high degree of sensitivity and specificity for determine the incidence of moderate and severe HIE,it provided an important basis for diagnosis of moderate and severe HIE.