Objective To explore the clinical features of intractable epilepsy caused by CACNA1E gene mutation. Method The clinical data of intractable epilepsy caused by CACNA1 E gene mutation in a child were retrospectively analyzed. Results A boy, aged 1 year and 6 months, was brought to the clinic due to intractable epilepsy with mental and motor retardation. He had hypotonia and severe epileptic encephalopathy performance. Genetic testing found that the child carried a new heterozygous mutation of c. 4258 (exon 30 ) G>A (NM_ 001205293 ) in CACNA 1 E gene, and both his parents were wildtype at this locus. The variant was classified as likely pathogenic according to the ACMG (The American College of Medical Genetics and Genomics) criteria ( 2015 ). Conclusion For children with intractable epilepsy accompanied by mental retardation and hypotonia, genetic testing should be performed as soon as possible to make a clear diagnosis.