Abstract: The contents of substances P （SP） and Zinc ion （Zn2+ ） in plasma. medulla oblongata. hypothalamus. pituitary,adrenal and kidney were determined by means of radioimmunoassay （RIA ） and atom absorption in Wistar rats in which the hypertension was induced by high dose estradilo. The results showed that after high-dose E2 treatment the contents of SP were increased in medulla oblongata and hypothalamus, but decreased in pituitary, adrenal and plasma;the contents of Zn2+ were increased in medulla oblongata, adrenal and plasma, but decreased in the kidney （P＜0. 05 0. 01）. These data indicate that SP is related to the process of hypertension induced by high-dose E2. E2 may enhance the blood pressure by changing the activity of some enzyrnes depending on Zn2+ in cardiovascu lar center of medulla oblongata,adrenal,kidney and plasma.