Objective To explore the clinical manifestations and prognosis of intractable epilepsy caused by SZT2 gene mutation in 3 children. Method Clinical data and follow-up results of 3 children with intractable epilepsy caused by SZT2 gene mutation were analyzed and summarized. Results Two boys and 1 girl presented intractable epilepsy at the age of 4 months, 10 months and 18 months respectively, accompanied by mental retardation, special facial features (high forehead, blepharoptosis, eyelid ptosis and bow shaped eyebrow), lower limb muscle tone and enlarged head circumference. All of them had severe epileptic encephalopathy, and one boy died of repeated convulsions (onset at age of 10 months). The genetic test results showed all of 3 children had SZT2 gene mutation. Conclusion For children having intractable epilepsy without obvious inducement accompanied by mental retardation, genetic testing should be completed as soon as possible to make a clear diagnosis.