Objective To study the effects on hippocampal neurons of epilepsy-induced rats with persistent(various) time courses of seizure.Methods 24 SD rats were divided randomly into 4 groups.Three groups of rats were status epilepticus(SE)-induced and differed in seizure-lasting time as follow respectively SE10 min,SE 10-30 min and SE30 min.The fourth was a control group.The ultrastructural morphological changes of hippocampal neuronal cell were observed by electron microscopy;The apoptosis related gene Bcl-2 and Bax proteins in hippocampous were investigated by using immunochemical method and the apoptotic neurons were detected by flow cytometry.Results Little change was seen in the first group,but the hippocampal neurons of the second group had significant apoptotic characters and the neurons showed necrotic features in the third.Conclusions SE triggers hippocampal neuronal degeneration comprised of both types necrosis and apoptosis,but which type is dominant depends on the duration of seizure activity.