Objective To explore the clinical manifestations and HCN 1 gene mutation in Dravet syndrome. Methods The clinical data and gene test results of Dravet syndrome in a child were retrospectively analyzed. Results The proband was a one year and 11 months old female who had recurrent febrile seizure onset from 4 months old, she presented with status epilepticus and various seizure types. Gene sequencing identified a de novo heterozygous mutation of c.1199 T>C (p.L400 P) in the HCN 1 gene. Conclusion The novel mutation of HCN 1 gene was classified as pathogenic, which enriched the mutation spectrum of Dravet syndrome.