Abstract: To investigate the role of stress and salt in the pathogenesis of hypertension,we observed the effect of chronic stress on renal sympathetic tone assessed by changes in renal sodium excretion and renal hemodynamic after denervation of the left kindey（LRNX）.The effect of high salt diet on blood pressure in rats who were chronically stressed was evaluated.Results:renal plasma flow（RPF）in the stressed rates was significantly lower than that in non stressed rats（2.9±0.2vs4.0±0.3ml／min／100g，P＜0.05）. LRNX restored the left kindey RPF in the stressed rats. LRNX increased the left kindey urine volume（UV）,and urinary sodium extent in the stressed rats（P＜0.05）.In rats with high salt in-take,chronic stress caused a gradual icrease in blood pressure（SAP）which reached the peak by the 12th day and the blood pressure was sustained thereafter.While in rats with high salt diet alone or subjected to stress alone,SAP remained unchanged during the 2 weeks of observation.It is suggested that chronic stress could increase the tonic effect of sympathetic nerve on the kidney,leading to a decreased ability in sodium excretion.Hypertension may develope when these animals were exposed to high salt diet.