Aim: To study the effects of angiotensin Ⅱ on stress-induced hypertension.Methods: Employing the electric foot shock and the noise of buzzer as stressors,we set up the rat models of acute and chronic stress-induced hypertension. The angiotensin Ⅱ content was detected by means of radioimmunoassay.Results: In the acute stress hypertensive rat, the angiotensin Ⅱ content was markedly increased in plasma, adrenal (P<0. 001 and P<0. 01 ), aorta and hypothalamus (P<0. 05); there was no significant change in myocardium and medulla oblongata. In the chronic stress hypertensive rat, the angiotensin Ⅱ content was elevated in cardiovascular and brain tissues; there was no considerable change in plasma and adrenal.Conclusion: These data suggest that the angiotensin Ⅱ in plasma and adrenal tissue is mainly associated with acute stress-induced hypertension; the angiotensin Ⅱ in cardiovascular and brain tissues is mainly assocaited with chronic stress-induced hypertension.