Abstract: Obiective To observe the effects of carbamazepine on morphology and glial fibrillary acidic protein (GFAP)expression of astrocytes in hippocampus of Sprague-Dawley rats.Methods Once daily intragastrically,in therapeutical dose for 1 week,1 and 3 months, the changes of astrocytic expression were observed with GFAP immunohistochemical staining. Results Compared to control group,GFAP immunoreactivity and the number of GFAP- positive astrocytes were significantly increased after 3 months of carbamazepine administration.Conclusion It is concluded that the changes of astrocytic expression induced by carbamazepine are time-dependent .