We reported a 41-day-old girl starting with partial status convulsivus. She had suffered from infantile epileptic encephalopathy manifesting with recurrent focal motor status convulsivus, eventually requiring general anesthesia for the treatment. She had had never myoclonic seizures nor tonic spasms. The examinations including brain MRI scan and metabolic screening tests were all negative. The ictal EEGs showed the onset of the seizures from the left frontal region. Interictal EEG demonstrated multifocal spike discharges as well as discontinuous abnormal EEG pattern resembling suppression-burst during sleep. The seizures were resistant to the multiple antiepileptic drugs, but zonisamide achieved full seizure control as well as improvement of the EEG. Her psychomotor development was severely retarded at 3 years of age.