Abstract: Objective To explore the relationship between hypoxic-ischemic encephalopathy (HIE) of newborn and the polymorphism of angiotensin converting enzyme (ACE) gene to find the susceptible gene of HIE by analyzing the polymorphism of the ACE gene in order to intervene early in the perinatal stage and reduce the incidence of HIE of newborn. Methods The polymorphism of ACE genes of 51 newborns with HIE and 53 normal newborns were analyzed with PCR-RFLP. Results There were three kinds of genotypes of ACE gene ：DD,ID and II. In the observation group, the distribution frequency of the D allele (56.9%) was higher than that in the control group (34.0%), the difference was statistical significant (P<0.005). Conclusion The significant association between the ACE genotype and HIE of newborn is found, D allele gene may be the susceptible gene of HIE.

Key words: polymorphism, restriction fragement length, brain, hypoxia-ischemia, peptidy1-dipeptidase A