After Cassia mimosoides var. nomame was treated with Phytolacca americana extracts during the germination process, its effect on the activities of AsPOX and GuPOX were examined. As the concentration of P. americana extract increased, the activity of AsPOX decreased while that of GuPOX increased. During the germination process, the activity of AsPOX was lower than the control, while the activity of GuPOX was over 2 times higher than the control. Activity of total peroxidase by IEF was extremely high at pI 6.4 and pI 6.6 when treatment was made with a 30% concentration of P. americana extract. The treatment with phenolic compounds, caffeic acid and benzoic acid did not show much difference from the control although a slight increase was observed at pI 6.6. Activity of GuPOX in C. mimosoides was over 4 times higher in roots than in shoots. Namely, because GuPOX activity of C. mimosoides was increased by extracts of P. americana, defense enzyme, GuPOX, was generated against external stress, and we could certified the activity increase at pI 6.4, especially in root.