The objective of this study is to evaluate a method that could be used in real-time arterial compliance estimation while measure blood pressure noninvasively. The noninvasive pressure waveform at carotid artery and pressure volume relation (PVR) at brachial artery were first evaluated to assert the consistency of compliance calculation. The arterial pressure waveform was acquired using oscillometric method. The result was checked against the data calculated using invasive pressure waveforms at aortic root and brachial artery that were acquired simultaneously. The result showed that the relaxation constant could be used to reveal stiffness of artery. The index could be assessed using pulse waveform acquired oscillometric method.