Objective: To investigate the expression of A-type potassium channel Kv4.1 in the CA1,CA3 and DG regions of the hippocampus in rats with pentylenetetrazol(PTZ)-induced epilepsy.Methods: Forty SD rats were randomly divided into normal control and epilepsy groups(including 3 subgroups: 1,24 and 72 hrs after the epilepsy events).Epilepsy was induced by injecting PTZ.Kv4.1 protein was detected in the CA1,CA3 and DG regions of the hippocampus using immunohistochemical and Western Blot analysis.Results: The Kv4.1 protein expression in the hippocampus in the epilepsy groups was significantly higher than in the control group(P<0.05).There were no significant differences in the expression of Kv4.1 protein among the three epilepsy subgroups.Conclusions: The expression of A-type potassium channel Kv4.1 protein in the hippocampus of epileptic rats increased,and the increased expression of Kv4.1 might play a role in the pathogenesis of epilepsy.