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 Astrocytic expression was 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 The changes of astrocytic expression induced by carbamazepine are time-dependent.