An electroviscous fluid which consists essentially of a non-conductive liquid and, dispersed therein, anhydrous spherical multilayered particles comprising particles at least whose surfaces are conductive and, formed thereon, a non-conductive layer having a thickness of about 0.1 to 1 .mu.m. The electroviscous fluid is stable at both ambient temperature and elevated temperatures, i.e., up to at least about 200.degree. C. in an applied electric potential with an alternating current or a pulsating direct current.