Abstract: Objective To explore the effect of Hyperbaric Oxygen (HBO) on the apoptosis resulted from Hypoxic-Ischemic Brain Damage (HIBD)，and to observe the changes in Caspase-3 expression. Methods Rats were divided into HIBD、HBO、sham operation group(n=24).To observe the morphologic change of brain tissues treated by HBO and compared with that of the Hypoxia-ischemia rat model, then check the dynastic change of Caspase-3 expression by immunohistochemistry at different time point. Results The expression of Caspase-3 in the hippocampus and cortex was higher than that of sham group at 18, 24, 48 and 96h time point（P<0.05）. The increased Caspase-3 expression decreased significantly in the brain of HIBD rats after HBO treatment (P<0.05). Conclusions HBO decreased the expression of Caspase-3 in hippocampus and cortex of HIBD rats.

Key words: Caspase-3, apoptosis, Hyperbaric Oxygen, Hypoxic-Ischemic Brain Damage