Genetic generalized epilepsies (GGEs) are a group of epilepsy syndromes caused by genetic factors. A few of GGEs conform to the Mendelian patterns, while most of them show polygene inheritance. Researchers initially found that most of the genes associated with GGEs are related to ion channels including voltage-gated sodium channels, potassium channels, calcium channels and chloride channels, and ligand-gated gamma-aminobutyric acid receptor channels. Further researches have shown that certain non-ion channel genes are also related to GGEs, and that de novo mutations and copy number variants also play an important role in the pathogenesis of GGEs. Application of next- and third-generation sequencing promoted delineation of the molecular genetics of the GGEs, but also brought more challenges. Genetic findings have provided an important basis for the elucidation of the pathogenesis, clinical diagnosis and precise treatment of GGEs. This paper provided a review for recent progress made in molecular genetics of GGEs.