Objective   To investigate the effects of enriched environment and impoverished environment on brain function after hypoxic-ischemic brain damage (HIBD).    Methods   Three-day-old SD rats

which were divided into enriched environment group (EE)

standard environment group (SE) and impoverished environment group (IE) by random digits table were used to establish HIBD model. The sham-operation rats served as control group. Different environment stimulations were administrated to the rats respectively since the 2nd day after HIBD. On the 32nd day

hanging test and incline plane test were carried out to evaluate the sensorimotor function. Morris water maze was used to evaluate the learning and memory ability. The expression of GFAP in the cortex and hippocampus was measured by the method of immunohistochemistry.    Results   The brain function of IE group was much worse than that of SE group (P0.01)

and the function of SE group was worse than that of sham group and EE group（P0.01）. There was no significant difference between sham group and EE group (P0.05).Immunohistochemical analysis showed the expression of GFAP in the cortex and hippocampus of Sham group was significantly lower than that of other groups (P0.01)

and the expression of GFAP of SE group was lower than that of EE group

but higher than that of IE group （P0.01）.    Conclusion   Enriched environment stimulation increases the expression of GFAP in the brain of premature rats after HIBD

and improves the brain function. Impoverished environment stimulation impairs the brain function.