Purpose: Encephalitis is a severe inflammatory disorder of the brain with many possible causes and with difficult differentiate of diagnosis. Existing criteria for autoimmune encephalitis are too reliant on antibody testing and response to immunotherapy, which might delay the diagnosis. Several particular features raise the suspicion of an autoimmune cause in otherwise unexplained seizure disorders. One of the most important challenges is the elucidation of the causes of seizure disorders. We presented one case of unexplained coma and refractory status epilepticus. Patient, 20 yars old.men, was admetted in hospital with coma , stable hemodinamics, on mechanical ventilation. On MRI research was discovered existence of inflammatory infiltration.At primery stage , EEG- discovered polymorphic dysrhythmia,bilateral activity,than plural peak shurp-slow wave paroxysms and status epilepticus. It was conducted combinated treatment with anticonvulsive drugs ,Immunoglobulin, pulse corticosteroid therapy with methylprednizolone and plazma exchange therapy. Conclusion: An autoimmune cause was suspected based on frequent or medically intractable seizures and the presence of neural antibody, inflammatory changes indicated in spinal fluid and on MRI. Patients had abnormal findings on brain MRI, with extensive multifocal or diffuse cortical and subcortical involvement. EEG showed generalized periodic discharges and status epilepticus . within investigation of IgG autoantibodies against proteins on the surfaces of neurons, we received difference result from two different laboratory,but refractory status epilepticus,radiological changes ,EEG pattern and progress of illness has indicated autoimmune character of process.