The existing detecting instruments for arteriosclerosis are usually expensive and bulky. To overcome their disadvantages, a novel portable noninvasive detecting instrument for arteriosclerosis based on advanced RISC machines (ARM) and WinCE is developed and its clinical assessment experiment is carried out. Its hardware platform is an embedded system. The pulse wave signals of radial artery and brachial artery are acquired by signal measurement circuit and transmitted to ARM processor. On the basis of arterial Windkessel model and oscillometric theory, pulse wave signals analysis is performed by custom-designed software based on LabVIEW for WinCE platform, and 11 arterial stiffness assess factors are calculated. Subject’s degree of arteriosclerosis is evaluated automatically by this instrument according to these factors. The results of clinical experiment show that the instrument can accurately evaluate degree of arteriosclerosis and keep good stability and reliability. The maximum relative error of stability is 4.37%, and the correlation coefficient with the consulted instrument is higher than 0.85 (P<0.001).