In patients being resuscitated successfully after cardiac arrest, electroencephalogram reactivity (EEG-R) is considered as a prognostic indicator. However, there are no clear guidelines on how to test EEG-R and exact definition of EEG-R. The International consensus on electroencephalogram reactivity testing after cardiac arrest on 2018, which is jointly developed by expert in relevant fields from many countries, reach a partial consensus on the test stimulation plan and definition of EEG-R. This paper interprets the main points of the consensus to provide reference for doctors majored in relevant fields in China.