Background and objectives: Pulse wave velocity(PWV) is a well known parameter for arterial stiffness. In the pharmacologic intervention studies on PWV, it is very difficult to evaluate the effect of blood pressure(BP) itself. And it is controversies if some antihypertensive medications have beyond blood pressure lowering effect on arterial stiffness in human subjects. Subjective and Methods: With an acute blood pressure lowering using sublingual nitroglycerin, the blood pressure, heart rate and baPWV were examined. For 70 subjects, nitroglycerin 0.6mg was administered sublingually in supine position after baseline measurements. After 8 minutes, follow up measurements were done. Result: Age was 60.3짹0.63 yrs. Male subjects were 60%. Body mass index was 24.6짹2.9 kg/m2. With sublingual nitroglycerin, heart rate was increased by 4.7 짹 5.2. Brachial BP was decreased by 8.4 짹7.1mmHg, 7.7짹5.6mmHg and 9.1짹6.6mmHg in systolic, diastolic and mean BP(p < 0.0001). The pulse pressure has no significant change(51.4짹11.1 vs 50.6짹8.7 mmHg, p=0.33). Ankle BP has bigger BP changes and ankle pulse pressure was decreased by 4.9짹7.7 mmHg. baPWV was decreased by 256.9 짹 156.5cm/s(1589.1짹301.8 vs 1332.2 짹 230.0 cm/s, p < 0.0001). ��baPWV(cm/s) = -11.3 * ��mean BP(mmHg) - 152.4(p<0.0001). Baseline baPWV(棺=-0.777, p=0.001), baseline mean BP(棺=0.343, p=0.001) and ��mean BP(棺=0.349, p=0.001). Conclusion: This study suggests that blood pressure changes frequently observed in clinical practice may have profound influence on arterial stiffness which should be considered when interpreting the efficacy of antihypertensive drugs on arterial stiffness.