Synchronization is one of the basic characteristics of EEG, which is of great significance to the study of EEG. But the synchronous evaluation methods of EEG are calculated according to local EEG, it reflects the local state of brain without considering the overall activity of the brain, so this is important for a new synchronous evaluation index of the overall state of the brain. Based on the information theory, this article gives a process of synchronization index from the calculation of ECoG. Using the process, the experimental gets the index IRAA and IMA2 as evaluation index of EEG global ...