 Arterial pulse wave velocity PWV is strongly correlated with atherosclerosis, and the PWV of carotid or femoral artery could predict the severity of arterial atherosclerosis. Because the measurement of PWV is noninvasive, it would serve as a good clinical and screen marker to evaluate the extent of atherosclerosis. The study uses self-made PWV measurement device to investigate the correlation of the PWV in the high cardiovascular risk population, and compare it with normal population. 