On May 11, 2012, Dr. Ren Liankun gave a lecture on “The application of broadband EEG in clinical practice” at the “3rd China Association Against Epilepsy (CAAE) China EEG and Neurophysiology Conference” in Changsha, Hunan Province. Dr. Ren Liankun gave a lecture on “Wide Band EEG in Clinical Applications”, which aroused wide interest of the participants. Abnormal brain electrophysiology is the essential feature of epilepsy. The analysis of EEG activity recorded by scalp and intracranial electrodes is the most important tool for studying the electrophysiology of epilepsy. Since EEG activity at different frequencies reflects different physiopathological mechanisms, frequency characteristics are the most critical factor in the analysis of EEG activity, but currently conventional EEG records only EEG activity in a very narrow frequency band between 0.5 and 70 Hz (δ activity at 0.5-3 Hz; θ activity at 4-7 Hz; α activity at 8-13 Hz; β activity at 14-30 Hz and γ activity at 30- 70Hz γ activity), which is the result of a large number of neurons (millions or more) involved in firing over a wide spatial range and synchronized. Because slower and faster EEG activity is selectively filtered out, conventional EEG recordings lose a great deal of macroscopic and subtle EEG information, which has limitations in the clinical and therapeutic management of epilepsy. In recent years, with the development of digital technology and the increased use of intracranial electrodes in clinical settings, people have been able to record EEG signals in vivo in the range of ultra-slow (0.001 Hz) to ultra-fast (thousands of Hz), i.e., broadband EEG, thus expanding the observation of EEG activity from millisecond-level temporal resolution of neuronal action potentials to slow activity frequencies of several minutes to tens of minutes or more. excitatory changes in the brain. The application of broadband EEG provides an unprecedented opportunity to accurately locate the source of epilepsy, to obtain better surgical results and to investigate the mechanism of electrophysiological abnormalities in epilepsy in depth.