Abstract: 　Objective　To investigate the clinical features and treatment of a group of patients of mitochondrial encephalomyopathy with actic acidosis and stroke (MELAS) with onset of status epileptics. Methods Clinical features, EEGs, image findings, and therapeutic data of 4 cases with onset of status epileptics patients finally diagnosed as MELAS were retrospectively reviewed. Results　Four Patients were onset with status epileptics. The levels of serum lactic acid, ammonia, myocardial enzymes were increased, and the serum sodium level was reduced, and accompanied with metabolic acidosis. EEG found corresponding paroxysmal and interictal activities. Brain images showed basal ganglia calcification, brain atrophy, and acute cortex edema. Genetic detection found mtDNA3243 mutation. Conclusions The status epilepticus was commonly present in MELAS. The treatment of epileptic attack in this disease was difficult, which needs early diagnosis. Appropriate anti-leptic drugs and relevant treatment to symptoms are important to alleviate cerebral injury.