Abstract: Ginseng is a typical adaptogen which has resistance to various stresses. This effect is related to the hypothalamic-pituitary-adrenal (HPA) axis. As the main active ingredients, saponin has the similar structure to steroids. The regulation characteristics of ginseng saponin on the HPA axis are narrated from the aspects of total saponin and saponin monomers in this paper after the introduction of adaptation definition and HPA axis regulation mechanisms. Pharmacological effects of ginseng saponin and the regulation effect of HPA axis are summarized finally.