Repeated immunization induces strong stress to kill mice. Ginsenosides have adaptogenic activities to cope with animal stresses. Mice treated with a ginsenoside may escape from the anaphylactic death. In the present study, effects of ginseng extract and ginsenosideRb1 on the death was examined. Mice were repeatedly given immunization stress. Fifty or 60 percent of them were dead at the third immunization. All mice treated with ginseng extract at the third immunization escaped from the anaphylactic death. GinsenosideRb1 dose-dependently prevented the anaphylactic death. These suggest that ginsenosideRb1 coped with the strong stress induced by repeated immunization. The present findings help to elucidate stress-coping mechanism of animals.