When we carried out an anti-stress study using the extracts of A. senticosus, R. coreanus, F .japonica root, and A. fruticosa fruit grown in Korea, the results showed that blood cell counts returned to normal levels fastest with R. coreanus after stress application. The total WBC count was decreased in mice due to stress, whereas the number of lymphocytes was increased. The serum glucose level was higher in the control group compared with the comparative stress group. The weight of each organ to returning to normal level was significantly faster in those mice treated with the extracts compared with those in control groups. Especially, it even return to that of normal level with R. coreanus extract, suggesting that the administration of the plant extracts in this study would affect hormonal activities in the body to increase immune activities. F. japonica root that showed the highest anti-stress activities maybe effective for lipid and carbohydrate metabolism. These results would provide basic data to examine anti-stress effects of natural plants. Further in-depth studies could contribute in the development of functional plant materials with anti-stress activities.