Objective: Febrile seizures are the most common seizures in children less than 5 years(2-5%),and the risk of its recurrence is 50%(>1year),30%(<1year).We focused on the effect and safety of the prophylaxis treatment of recurrent FS beacuase it is a terrifying case for the parents. Materials&Methods:This is a trial study on 40 patient with FS.Clonazepam was recommended 0.05mg/kg/d then anti e when fever exceed 38°.We did follow up every 3 month during one year. Results:we followed 35 patient, familial history of FS found in 57.1%,a history of epilepsy in 28.57%.clonazepam side effects were supportable the most common was lawson 14.28%,the efficacy of the treatment we didn’t noticed any episode of FS during the study 97.1%. Conclusion: Clonazepam is a safe and effective and easy treatement for the parents for the prophylaxis of FS recurrence.