Objective: N-Type calcium channel antagonists may suppress sympathetic activity. We evaluated the effects of cilnidipine and amlodipine on the sympathetic nervous system and the central and systemic arterial stiffness of essential hypertension. Methods: Thirty-three untreated patients with uncomplicated essential hypertension (49짹6years; 45% male; BP 169짹16/104짹6mmHg) were randomly assigned to 10 to 20mg/d cilnidipine or 5 to 10mg/d of amlodipine for 3 months. For comparison, 38 normotensives (50짹8years; 50% male; BP 115짹13/71짹10mmHg) were studied. Systemic arterial stiffness (augmentation index; AI), subendocardial viability index (SEVR) and the response to salbutamol (400關g) which would allow assessment of global endothelial function, were measured using radial pulse tonometry and local arterial stiffness (棺-index) was evaluated by echocardiogram. Plasma norepinephrine (NE) concentration was also measured. Results: No significant differences were found in the basal characteristics among the normotensive and 2 hypertensive groups. The hypertensives had significantly higher local stiffness (carotid and aortic 棺) and systemic stiffness (AI) (all, p>0.01) and endothelial dysfunction (5.6 vs. 11.5% decrease of AI of normotensives, p<0.05). SEVR was similar in both groups. Plasma NE was higher in hypertensive patients (72짹52pg/ml) than control subjects (57짹37pg/ml). After 3 months treatment, systolic and diastolic blood pressures significantly decreased from the baseline values in cilnidipine and amlodipine groups, with no significant differences between the groups. Both drugs improved equally the systemic and local stiffness. In the cilnidipine group, however, a significant decrease in NE (41% reduction, p<0. 05) was noted, without change in the amlodipine group. No significant change was found in SEVR and endothelial dysfunction in either group. Conclusion: in patients with essential hypertension, both cilnidipine and amlodpine similarly reduced vascular stiffness. However, only cilnidipine suppressed sympathetic nerve activity, whereas amlodipine had no effect. Cilnidipine may provide more beneficial effect on the management in arteriosclerotic hypertension with sympathetic overactivity.