Backgroud and Objectives : The islated systolic hypertension (ISH) is closely related to the arterial stiffness of large sized-vessel. The object of this study was to investigate hemodynamics and arterial stiffness by invasive method after nitrate intravenous injection. Subjects and Methods : 20 subjects who underwent coronary angiography without any significant lesion were enrolled. After intravenous injection of 2mg isosorbide dinitrate, every 1minute to 5 minutes, electrocardiography and pressure curves of aorta and right femoral artery were recorded simultaneous using polygraphy. Pulse wave velocity (PWV) and augmentation index (AI) were measured using the electric caliper. Results : systolic blood pressure (SBP) was dropped (p<0.001)significantly just 1 minute after nitrate injection but no diastolic blood pressure (DBP) change was found. The effect was maintained to 5 minutes after nitrate injection. Pulse pressure (p<0.001), PWV (p=0.05) and AI (p<0.013) also significantly decreased after 1 minute of injection and sustained to 5 minutes. These effects were not influenced by the sex, age, BMI, diabetes mellitus and dyslipidemia, but the patients taking antihypertensive drugs revealed no significant change of PWV (p=0.074). Conclusion : Intravenous injection of isosorbide dinitrate was very effective to control the SBP without any DBP change in ISH patients. And it is also expected to prevent the progression of arterial stiffness by improving PWV and AI.