Objective To study the effect and significance of hyperbaric oxygen treatment on the expression of neuroglobin by observing the changing tendency of neuroglobin in mouse hippocampus after forebrain ischemiareperfusion. Methods Eighteen female C57BL/6N mice were divided into three groups randomly: the shamoperated control group, the 48hour ischemiareperfusion group (48h I/R) and the group treated with hyperbaric oxygen after 48hour ischemiareperfusion (48h HBO). HE staining and immunohistochemistry experiments were carried out on the brains of all the animals. Image analysis and statistical treatment were also performed for all the images. Results The neuroglobin expression level of 48h I/R group and the 48h HBO group were higher than that of the shamoperated group (P<0.01 and P<0.001, respectively); the optical density of the 48h HBO group was higher than that of the 48h I/R group(P<0.01).Conclusion Hyperbaric oxygen treatment had an obvious effect on ischemic brain injury, and increasing t