Abstract: Objective:To investigate the effects of hypoxic post-treatment on neonatal rats with hypoxic-ischemic brain damage.Methods:Two hundred and four SD rats were randomly divided into the HIBD group,sham operation group,8% O₂ combined with 92% N₂ group(hypoxic group A),and 15% O₂ combined with 85% N₂ group(hypoxic group B)(51 rats each group).The levels of hypoxia inducible factor(HIF)-1α and learning and memory abilities between four groups were compared.Results:The differences of the levels of HIF-1α in brain tissue between four groups were statistically significant(P<0.01),the level of HIF-1α expression in hypoxic group A was the highest,which gradually decreased in hypoxia group B,sham operation group,and HIBD group in turn.There were statistical significances in the study latency,memory latency,and number of learning errors and memory errors between four groups(P<0.01),the four indictors in sham operation group were significantly better than those in other three groups(P<0.01),the memory latency and number of learning errors in hypoxia group A and hypoxia group B were significantly less than those in HIBD group(P<0.05 to P<0.01),and the study latency in hypoxia group A was less than that in HIBD group(P<0.05).Conclusions:The hypoxic post-treatment in neonatal rats with hypoxic-ischemic brain damage can effectively promote the expression of HIF-1α,and enhance the learning and memory abilities of newborn rats.