Abstract: Electroantennogram (EAG) technique is an electrophysiological method which directly to detect insect responses to chemical signal, and has been widely used in the antenna responses of Orthoptera, Hymenoptera, Diptera, Coleoptera, etc to semichemicals. This article described briefly the theory, basic structure and development of EAG, experimental attentions and limitations of the EAG technique, all of which aiming to provide a clear thinking for studying electrophysiological behavior and to make some help for solving the problems.