Abstract: 　Objective　To explore the clinical features and treatment strategy of severe anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis in children. Methods　The clinical data and follow-up information of 4 children with severe anti-NMDAR encephalitis were retrospectively analyzed. Results　Four patients (one male and 3 females) were 10 to 13 years old and one child had teratoma combined. In all patients symptoms at onset mainly were psychiatric syndrome and movement disorder, and then progressed to seizures, disturbance of consciousness and central hypoventilation respiratory failure in one month. The anti-NMDAR antibodies in cerebrospinal fluid were positive in all patients. The EEG showed focal or diffuse slow waves. The brain MRI showed no pathological changes at the diagnosis. The treatment included methylprednisolone and large doses of intravenous immunoglobulin (IVIG), ventilator for 5-95 days, and tracheotomy in 2 cases. One case died because of serious infection. In 21-27 months of the follow-up, one case had clinical recovery; 2 cases had the sustained use of immunosuppressive agents and anti-epileptic drugs and the clinical symptoms were significantly improved. The EEG and antiNMDAR antibodies continued abnormal in the patient combined with teratoma. One patient relapsed. Conclusions　The severe anti-NMDAR is more likely in older female children. The central hypoventilation respiratory failure occurs in the early course of the disease. Combination with tumor is high risk factor. Conventional hormone therapy and ventilator treatment is effective. The recovery is slow. It may be relapsed even one year later.