The fundamental characteristics of “stick-slip” motion in a machine tool slideway is ascertained experimentally, and it is clarified that the time-dependence of static friction has a great influence on the behavior of the stick-slip motion. An empirical formula is proposed to express the characteristics of static friction and the mechanism of the time-dependence of static friction is examined experimentally and theoretically. The influence of properties of lubricants and surface topography on the static friction is investigated quantitatively. Finally, a general conception to prevent stick-slip motion is offered.