The decapeptide gonadotropin-releasing hormone（GnRH）is a kind of regulative neuropeptide synthesized by GnRH-producing cell bodies in hypothalamus and is an important information molecule among nervous, immune and neuroendocrine systems. GnRH plays a pivotal role in the regulation of reproduction. In recent years, GnRH-analogues have been one of the most widely applied hormonal medicine. The research progresses of GnRH were reviewed, including structure, localization and distribution of GnRH and its receptor. A series of evidences on GnRH regulating reproduction activity at different levels such as pituitary and gonad, factors affecting secretion of GnRH, as well as prospects of studies on GnRH are also introduced.