Abstract: Infantile epileptic spasm syndrome (IESS) is a new concept proposed recently. IESS is a unique and age-specific refractory epilepsy syndrome. The recent advances in molecular biology, neuroimmunology and the in-depth study of anti-epileptic mechanism in antiepileptic drugs have led to the achievements in the definition and treatment of infantile epileptic spasm. At present, the use of traditional antiepileptic drugs is decreasing, while the use of new antiepileptic drugs is increasing. In this paper, based on the relevant literature in recent years, the authors discuss the pathogenesis, epidemiology, etiology, diagnosis, treatment, therapeutic drugs, clinical progress, efficacy, and safety of infantile epileptic spasm, hoping to introduce the latest status in research and achievements of IESS.